Update nlopes/slack vendor

57 files changed, 2636 insertions, 2029 deletions

diff --git a/go.mod b/go.mod
index 7e2d5053..2d6107bf 100644
--- a/go.mod
+++ b/go.mod
@@ -41,13 +41,14 @@ require (
 	github.com/mreiferson/go-httpclient v0.0.0-20160630210159-31f0106b4474 // indirect
 	github.com/mrexodia/wray v0.0.0-20160318003008-78a2c1f284ff // indirect
 	github.com/nicksnyder/go-i18n v1.4.0 // indirect
-	github.com/nlopes/slack v0.0.0-20180101221843-107290b5bbaf
+	github.com/nlopes/slack v0.3.1-0.20180805133408-21749ab136a8
 	github.com/onsi/ginkgo v1.6.0 // indirect
 	github.com/onsi/gomega v1.4.1 // indirect
 	github.com/paulrosania/go-charset v0.0.0-20151028000031-621bb39fcc83
 	github.com/pborman/uuid v0.0.0-20160216163710-c55201b03606 // indirect
 	github.com/pelletier/go-toml v0.0.0-20180228233631-05bcc0fb0d3e // indirect
 	github.com/peterhellberg/emojilib v0.0.0-20170616163716-41920917e271
+	github.com/pkg/errors v0.8.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rs/xid v0.0.0-20180525034800-088c5cf1423a
 	github.com/russross/blackfriday v1.5.1
diff --git a/go.sum b/go.sum
index 19b946a7..99fffb38 100644
--- a/go.sum
+++ b/go.sum
@@ -83,6 +83,8 @@ github.com/nicksnyder/go-i18n v1.4.0 h1:AgLl+Yq7kg5OYlzCgu9cKTZOyI4tD/NgukKqLqC8
 github.com/nicksnyder/go-i18n v1.4.0/go.mod h1:HrK7VCrbOvQoUAQ7Vpy7i87N7JZZZ7R2xBGjv0j365Q=
 github.com/nlopes/slack v0.0.0-20180101221843-107290b5bbaf h1:M+xGhDxie/MqC+tzs+3ZHBSY4Wsv+fEkrpIMCKy8PTg=
 github.com/nlopes/slack v0.0.0-20180101221843-107290b5bbaf/go.mod h1:jVI4BBK3lSktibKahxBF74txcK2vyvkza1z/+rRnVAM=
+github.com/nlopes/slack v0.3.1-0.20180805133408-21749ab136a8 h1:PSy8NkmkyldLmPPnNNw7mwfQFOHDqOI6bINpJ+/KV7Y=
+github.com/nlopes/slack v0.3.1-0.20180805133408-21749ab136a8/go.mod h1:jVI4BBK3lSktibKahxBF74txcK2vyvkza1z/+rRnVAM=
 github.com/onsi/ginkgo v1.6.0 h1:Ix8l273rp3QzYgXSR+c8d1fTG7UPgYkOSELPhiY/YGw=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.4.1 h1:PZSj/UFNaVp3KxrzHOcS7oyuWA7LoOY/77yCTEFu21U=
@@ -95,6 +97,8 @@ github.com/pelletier/go-toml v0.0.0-20180228233631-05bcc0fb0d3e h1:ZW8599OjioQsm
 github.com/pelletier/go-toml v0.0.0-20180228233631-05bcc0fb0d3e/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/peterhellberg/emojilib v0.0.0-20170616163716-41920917e271 h1:wQ9lVx75za6AT2kI0S9QID0uWuwTWnvcTfN+uw1F8vg=
 github.com/peterhellberg/emojilib v0.0.0-20170616163716-41920917e271/go.mod h1:G7LufuPajuIvdt9OitkNt2qh0mmvD4bfRgRM7bhDIOA=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rs/xid v0.0.0-20180525034800-088c5cf1423a h1:UWKek6MK3K6/TpbsFcv+8rrO6rSc6KKSp2FbMOHWsq4=
diff --git a/vendor/github.com/nlopes/slack/.gitignore b/vendor/github.com/nlopes/slack/.gitignore
index dd2440d5..ac6f3eeb 100644
--- a/vendor/github.com/nlopes/slack/.gitignore
+++ b/vendor/github.com/nlopes/slack/.gitignore
@@ -1,2 +1,3 @@
 *.test
 *~
+.idea/
diff --git a/vendor/github.com/nlopes/slack/CHANGELOG.md b/vendor/github.com/nlopes/slack/CHANGELOG.md
index 8c4772da..a79ea50c 100644
--- a/vendor/github.com/nlopes/slack/CHANGELOG.md
+++ b/vendor/github.com/nlopes/slack/CHANGELOG.md
@@ -1,3 +1,16 @@
+### v0.3.0 - July 30, 2018

+full differences can be viewed using `git log --oneline --decorate --color v0.2.0..v0.3.0`

+- slack events initial support added. (still considered experimental and undergoing changes, stability not promised)

+- vendored depedencies using dep, ensure using up to date tooling before filing issues.

+- RTM has improved its ability to identify dead connections and reconnect automatically (worth calling out in case it has unintended side effects).

+- bug fixes (various timestamp handling, error handling, RTM locking, etc).

+

+### v0.2.0 - Feb 10, 2018

+

+Release adds a bunch of functionality and improvements, mainly to give people a recent version to vendor against.

+

+Please check [0.2.0](https://github.com/nlopes/slack/releases/tag/v0.2.0)

+

 ### v0.1.0 - May 28, 2017

 

 This is released before adding context support.

diff --git a/vendor/github.com/nlopes/slack/Gopkg.lock b/vendor/github.com/nlopes/slack/Gopkg.lock
new file mode 100644
index 00000000..5cc0520e
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/Gopkg.lock
@@ -0,0 +1,33 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  name = "github.com/davecgh/go-spew"
+  packages = ["spew"]
+  revision = "346938d642f2ec3594ed81d874461961cd0faa76"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "github.com/gorilla/websocket"
+  packages = ["."]
+  revision = "ea4d1f681babbce9545c9c5f3d5194a789c89f5b"
+  version = "v1.2.0"
+
+[[projects]]
+  name = "github.com/pmezard/go-difflib"
+  packages = ["difflib"]
+  revision = "792786c7400a136282c1664665ae0a8db921c6c2"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/stretchr/testify"
+  packages = ["assert"]
+  revision = "f35b8ab0b5a2cef36673838d662e249dd9c94686"
+  version = "v1.2.2"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "888307bf47ee004aaaa4c45e6139929b4984f2253e48e382246bfb8c66f3cd65"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/vendor/github.com/nlopes/slack/README.md b/vendor/github.com/nlopes/slack/README.md
index 953b9d8f..849e8bdc 100644
--- a/vendor/github.com/nlopes/slack/README.md
+++ b/vendor/github.com/nlopes/slack/README.md
@@ -7,19 +7,20 @@ This library supports most if not all of the `api.slack.com` REST
 calls, as well as the Real-Time Messaging protocol over websocket, in
 a fully managed way.
 
+
+
 ## Change log
+Support for the EventsAPI has recently been added. It is still in its early stages but nearly all events have been added and tested (except for those events in [Developer Preview](https://api.slack.com/slack-apps-preview) mode). API stability for events is not promised at this time.
 
-### v0.1.0 - May 28, 2017
+### v0.2.0 - Feb 10, 2018
 
-This is released before adding context support.
-As the used context package is the one from Go 1.7 this will be the last
-compatible with Go < 1.7.
+Release adds a bunch of functionality and improvements, mainly to give people a recent version to vendor against.
 
-Please check [0.1.0](https://github.com/nlopes/slack/releases/tag/v0.1.0)
+Please check [0.2.0](https://github.com/nlopes/slack/releases/tag/v0.2.0)
 
 ### CHANGELOG.md
 
-As of this version a [CHANGELOG.md](https://github.com/nlopes/slack/blob/master/CHANGELOG.md) is available. Please visit it for updates.
+ [CHANGELOG.md](https://github.com/nlopes/slack/blob/master/CHANGELOG.md) is available. Please visit it for updates.
 
 ## Installing
 
@@ -79,6 +80,11 @@ func main() {
 See https://github.com/nlopes/slack/blob/master/examples/websocket/websocket.go
 
 
+## Minimal EventsAPI usage:
+
+See https://github.com/nlopes/slack/blob/master/examples/eventsapi/events.go
+
+
 ## Contributing
 
 You are more than welcome to contribute to this project.  Fork and
diff --git a/vendor/github.com/nlopes/slack/admin.go b/vendor/github.com/nlopes/slack/admin.go
index 478c4f40..a2aa7e5c 100644
--- a/vendor/github.com/nlopes/slack/admin.go
+++ b/vendor/github.com/nlopes/slack/admin.go
@@ -12,9 +12,9 @@ type adminResponse struct {
 	Error string `json:"error"`
 }
 
-func adminRequest(ctx context.Context, method string, teamName string, values url.Values, debug bool) (*adminResponse, error) {
+func adminRequest(ctx context.Context, client HTTPRequester, method string, teamName string, values url.Values, debug bool) (*adminResponse, error) {
 	adminResponse := &adminResponse{}
-	err := parseAdminResponse(ctx, method, teamName, values, adminResponse, debug)
+	err := parseAdminResponse(ctx, client, method, teamName, values, adminResponse, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -35,12 +35,12 @@ func (api *Client) DisableUser(teamName string, uid string) error {
 func (api *Client) DisableUserContext(ctx context.Context, teamName string, uid string) error {
 	values := url.Values{
 		"user":       {uid},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "setInactive", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "setInactive", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to disable user with id '%s': %s", uid, err)
 	}
@@ -61,12 +61,13 @@ func (api *Client) InviteGuestContext(ctx context.Context, teamName, channel, fi
 		"first_name":       {firstName},
 		"last_name":        {lastName},
 		"ultra_restricted": {"1"},
-		"token":            {api.config.token},
+		"token":            {api.token},
+		"resend":           {"true"},
 		"set_active":       {"true"},
 		"_attempts":        {"1"},
 	}
 
-	_, err := adminRequest(ctx, "invite", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "invite", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to invite single-channel guest: %s", err)
 	}
@@ -87,12 +88,13 @@ func (api *Client) InviteRestrictedContext(ctx context.Context, teamName, channe
 		"first_name": {firstName},
 		"last_name":  {lastName},
 		"restricted": {"1"},
-		"token":      {api.config.token},
+		"token":      {api.token},
+		"resend":     {"true"},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "invite", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "invite", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to restricted account: %s", err)
 	}
@@ -111,12 +113,12 @@ func (api *Client) InviteToTeamContext(ctx context.Context, teamName, firstName,
 		"email":      {emailAddress},
 		"first_name": {firstName},
 		"last_name":  {lastName},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "invite", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "invite", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to invite to team: %s", err)
 	}
@@ -133,12 +135,12 @@ func (api *Client) SetRegular(teamName, user string) error {
 func (api *Client) SetRegularContext(ctx context.Context, teamName, user string) error {
 	values := url.Values{
 		"user":       {user},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "setRegular", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "setRegular", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to change the user (%s) to a regular user: %s", user, err)
 	}
@@ -155,12 +157,12 @@ func (api *Client) SendSSOBindingEmail(teamName, user string) error {
 func (api *Client) SendSSOBindingEmailContext(ctx context.Context, teamName, user string) error {
 	values := url.Values{
 		"user":       {user},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "sendSSOBind", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "sendSSOBind", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to send SSO binding email for user (%s): %s", user, err)
 	}
@@ -178,12 +180,12 @@ func (api *Client) SetUltraRestrictedContext(ctx context.Context, teamName, uid,
 	values := url.Values{
 		"user":       {uid},
 		"channel":    {channel},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "setUltraRestricted", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "setUltraRestricted", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to ultra-restrict account: %s", err)
 	}
@@ -200,12 +202,12 @@ func (api *Client) SetRestricted(teamName, uid string) error {
 func (api *Client) SetRestrictedContext(ctx context.Context, teamName, uid string) error {
 	values := url.Values{
 		"user":       {uid},
-		"token":      {api.config.token},
+		"token":      {api.token},
 		"set_active": {"true"},
 		"_attempts":  {"1"},
 	}
 
-	_, err := adminRequest(ctx, "setRestricted", teamName, values, api.debug)
+	_, err := adminRequest(ctx, api.httpclient, "setRestricted", teamName, values, api.debug)
 	if err != nil {
 		return fmt.Errorf("Failed to restrict account: %s", err)
 	}
diff --git a/vendor/github.com/nlopes/slack/attachments.go b/vendor/github.com/nlopes/slack/attachments.go
index abc94e73..326fc010 100644
--- a/vendor/github.com/nlopes/slack/attachments.go
+++ b/vendor/github.com/nlopes/slack/attachments.go
@@ -59,6 +59,7 @@ type AttachmentActionCallback struct {
 	AttachmentID string `json:"attachment_id"`
 	Token        string `json:"token"`
 	ResponseURL  string `json:"response_url"`
+	TriggerID    string `json:"trigger_id"`
 }
 
 // ConfirmationField are used to ask users to confirm actions
@@ -75,7 +76,9 @@ type Attachment struct {
 	Fallback string `json:"fallback"`
 
 	CallbackID string `json:"callback_id,omitempty"`
+	ID         int    `json:"id,omitempty"`
 
+	AuthorID      string `json:"author_id,omitempty"`
 	AuthorName    string `json:"author_name,omitempty"`
 	AuthorSubname string `json:"author_subname,omitempty"`
 	AuthorLink    string `json:"author_link,omitempty"`
diff --git a/vendor/github.com/nlopes/slack/backoff.go b/vendor/github.com/nlopes/slack/backoff.go
index e555a1ad..197bce2e 100644
--- a/vendor/github.com/nlopes/slack/backoff.go
+++ b/vendor/github.com/nlopes/slack/backoff.go
@@ -38,7 +38,7 @@ func (b *backoff) Duration() time.Duration {
 	}
 	//calculate this duration
 	dur := float64(b.Min) * math.Pow(b.Factor, float64(b.attempts))
-	if b.Jitter == true {
+	if b.Jitter {
 		dur = rand.Float64()*(dur-float64(b.Min)) + float64(b.Min)
 	}
 	//cap!
diff --git a/vendor/github.com/nlopes/slack/bots.go b/vendor/github.com/nlopes/slack/bots.go
index 13a78cb1..92570a04 100644
--- a/vendor/github.com/nlopes/slack/bots.go
+++ b/vendor/github.com/nlopes/slack/bots.go
@@ -19,9 +19,9 @@ type botResponseFull struct {
 	SlackResponse
 }
 
-func botRequest(ctx context.Context, path string, values url.Values, debug bool) (*botResponseFull, error) {
+func botRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*botResponseFull, error) {
 	response := &botResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -39,10 +39,11 @@ func (api *Client) GetBotInfo(bot string) (*Bot, error) {
 // GetBotInfoContext will retrieve the complete bot information using a custom context
 func (api *Client) GetBotInfoContext(ctx context.Context, bot string) (*Bot, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"bot":   {bot},
 	}
-	response, err := botRequest(ctx, "bots.info", values, api.debug)
+
+	response, err := botRequest(ctx, api.httpclient, "bots.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/channels.go b/vendor/github.com/nlopes/slack/channels.go
index 9490bc70..6204315a 100644
--- a/vendor/github.com/nlopes/slack/channels.go
+++ b/vendor/github.com/nlopes/slack/channels.go
@@ -20,14 +20,15 @@ type channelResponseFull struct {
 // Channel contains information about the channel
 type Channel struct {
 	groupConversation
-	IsChannel bool `json:"is_channel"`
-	IsGeneral bool `json:"is_general"`
-	IsMember  bool `json:"is_member"`
+	IsChannel bool   `json:"is_channel"`
+	IsGeneral bool   `json:"is_general"`
+	IsMember  bool   `json:"is_member"`
+	Locale    string `json:"locale"`
 }
 
-func channelRequest(ctx context.Context, path string, values url.Values, debug bool) (*channelResponseFull, error) {
+func channelRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*channelResponseFull, error) {
 	response := &channelResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postForm(ctx, client, SLACK_API+path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -45,12 +46,13 @@ func (api *Client) ArchiveChannel(channelID string) error {
 
 // ArchiveChannelContext archives the given channel with a custom context
 // see https://api.slack.com/methods/channels.archive
-func (api *Client) ArchiveChannelContext(ctx context.Context, channelID string) error {
+func (api *Client) ArchiveChannelContext(ctx context.Context, channelID string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 	}
-	_, err := channelRequest(ctx, "channels.archive", values, api.debug)
+
+	_, err = channelRequest(ctx, api.httpclient, "channels.archive", values, api.debug)
 	return err
 }
 
@@ -62,12 +64,13 @@ func (api *Client) UnarchiveChannel(channelID string) error {
 
 // UnarchiveChannelContext unarchives the given channel with a custom context
 // see https://api.slack.com/methods/channels.unarchive
-func (api *Client) UnarchiveChannelContext(ctx context.Context, channelID string) error {
+func (api *Client) UnarchiveChannelContext(ctx context.Context, channelID string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 	}
-	_, err := channelRequest(ctx, "channels.unarchive", values, api.debug)
+
+	_, err = channelRequest(ctx, api.httpclient, "channels.unarchive", values, api.debug)
 	return err
 }
 
@@ -81,10 +84,11 @@ func (api *Client) CreateChannel(channelName string) (*Channel, error) {
 // see https://api.slack.com/methods/channels.create
 func (api *Client) CreateChannelContext(ctx context.Context, channelName string) (*Channel, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"name":  {channelName},
 	}
-	response, err := channelRequest(ctx, "channels.create", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.create", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -101,7 +105,7 @@ func (api *Client) GetChannelHistory(channelID string, params HistoryParameters)
 // see https://api.slack.com/methods/channels.history
 func (api *Client) GetChannelHistoryContext(ctx context.Context, channelID string, params HistoryParameters) (*History, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 	}
 	if params.Latest != DEFAULT_HISTORY_LATEST {
@@ -120,6 +124,7 @@ func (api *Client) GetChannelHistoryContext(ctx context.Context, channelID strin
 			values.Add("inclusive", "0")
 		}
 	}
+
 	if params.Unreads != DEFAULT_HISTORY_UNREADS {
 		if params.Unreads {
 			values.Add("unreads", "1")
@@ -127,7 +132,8 @@ func (api *Client) GetChannelHistoryContext(ctx context.Context, channelID strin
 			values.Add("unreads", "0")
 		}
 	}
-	response, err := channelRequest(ctx, "channels.history", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.history", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -144,10 +150,11 @@ func (api *Client) GetChannelInfo(channelID string) (*Channel, error) {
 // see https://api.slack.com/methods/channels.info
 func (api *Client) GetChannelInfoContext(ctx context.Context, channelID string) (*Channel, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 	}
-	response, err := channelRequest(ctx, "channels.info", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -164,11 +171,12 @@ func (api *Client) InviteUserToChannel(channelID, user string) (*Channel, error)
 // see https://api.slack.com/methods/channels.invite
 func (api *Client) InviteUserToChannelContext(ctx context.Context, channelID, user string) (*Channel, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"user":    {user},
 	}
-	response, err := channelRequest(ctx, "channels.invite", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.invite", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -185,10 +193,11 @@ func (api *Client) JoinChannel(channelName string) (*Channel, error) {
 // see https://api.slack.com/methods/channels.join
 func (api *Client) JoinChannelContext(ctx context.Context, channelName string) (*Channel, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"name":  {channelName},
 	}
-	response, err := channelRequest(ctx, "channels.join", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.join", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -205,17 +214,16 @@ func (api *Client) LeaveChannel(channelID string) (bool, error) {
 // see https://api.slack.com/methods/channels.leave
 func (api *Client) LeaveChannelContext(ctx context.Context, channelID string) (bool, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 	}
-	response, err := channelRequest(ctx, "channels.leave", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.leave", values, api.debug)
 	if err != nil {
 		return false, err
 	}
-	if response.NotInChannel {
-		return response.NotInChannel, nil
-	}
-	return false, nil
+
+	return response.NotInChannel, nil
 }
 
 // KickUserFromChannel kicks a user from a given channel
@@ -226,13 +234,14 @@ func (api *Client) KickUserFromChannel(channelID, user string) error {
 
 // KickUserFromChannelContext kicks a user from a given channel with a custom context
 // see https://api.slack.com/methods/channels.kick
-func (api *Client) KickUserFromChannelContext(ctx context.Context, channelID, user string) error {
+func (api *Client) KickUserFromChannelContext(ctx context.Context, channelID, user string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"user":    {user},
 	}
-	_, err := channelRequest(ctx, "channels.kick", values, api.debug)
+
+	_, err = channelRequest(ctx, api.httpclient, "channels.kick", values, api.debug)
 	return err
 }
 
@@ -246,12 +255,13 @@ func (api *Client) GetChannels(excludeArchived bool) ([]Channel, error) {
 // see https://api.slack.com/methods/channels.list
 func (api *Client) GetChannelsContext(ctx context.Context, excludeArchived bool) ([]Channel, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if excludeArchived {
 		values.Add("exclude_archived", "1")
 	}
-	response, err := channelRequest(ctx, "channels.list", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.list", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -271,13 +281,14 @@ func (api *Client) SetChannelReadMark(channelID, ts string) error {
 // SetChannelReadMarkContext sets the read mark of a given channel to a specific point with a custom context
 // For more details see SetChannelReadMark documentation
 // see https://api.slack.com/methods/channels.mark
-func (api *Client) SetChannelReadMarkContext(ctx context.Context, channelID, ts string) error {
+func (api *Client) SetChannelReadMarkContext(ctx context.Context, channelID, ts string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"ts":      {ts},
 	}
-	_, err := channelRequest(ctx, "channels.mark", values, api.debug)
+
+	_, err = channelRequest(ctx, api.httpclient, "channels.mark", values, api.debug)
 	return err
 }
 
@@ -291,13 +302,14 @@ func (api *Client) RenameChannel(channelID, name string) (*Channel, error) {
 // see https://api.slack.com/methods/channels.rename
 func (api *Client) RenameChannelContext(ctx context.Context, channelID, name string) (*Channel, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"name":    {name},
 	}
+
 	// XXX: the created entry in this call returns a string instead of a number
 	// so I may have to do some workaround to solve it.
-	response, err := channelRequest(ctx, "channels.rename", values, api.debug)
+	response, err := channelRequest(ctx, api.httpclient, "channels.rename", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -314,11 +326,12 @@ func (api *Client) SetChannelPurpose(channelID, purpose string) (string, error)
 // see https://api.slack.com/methods/channels.setPurpose
 func (api *Client) SetChannelPurposeContext(ctx context.Context, channelID, purpose string) (string, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"purpose": {purpose},
 	}
-	response, err := channelRequest(ctx, "channels.setPurpose", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.setPurpose", values, api.debug)
 	if err != nil {
 		return "", err
 	}
@@ -335,11 +348,12 @@ func (api *Client) SetChannelTopic(channelID, topic string) (string, error) {
 // see https://api.slack.com/methods/channels.setTopic
 func (api *Client) SetChannelTopicContext(ctx context.Context, channelID, topic string) (string, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channelID},
 		"topic":   {topic},
 	}
-	response, err := channelRequest(ctx, "channels.setTopic", values, api.debug)
+
+	response, err := channelRequest(ctx, api.httpclient, "channels.setTopic", values, api.debug)
 	if err != nil {
 		return "", err
 	}
@@ -356,11 +370,11 @@ func (api *Client) GetChannelReplies(channelID, thread_ts string) ([]Message, er
 // see https://api.slack.com/methods/channels.replies
 func (api *Client) GetChannelRepliesContext(ctx context.Context, channelID, thread_ts string) ([]Message, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"channel":   {channelID},
 		"thread_ts": {thread_ts},
 	}
-	response, err := channelRequest(ctx, "channels.replies", values, api.debug)
+	response, err := channelRequest(ctx, api.httpclient, "channels.replies", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/chat.go b/vendor/github.com/nlopes/slack/chat.go
index 0eb042df..2b89a44c 100644
--- a/vendor/github.com/nlopes/slack/chat.go
+++ b/vendor/github.com/nlopes/slack/chat.go
@@ -3,17 +3,16 @@ package slack
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"net/url"
 	"strings"
 )
 
 const (
 	DEFAULT_MESSAGE_USERNAME         = ""
-	DEFAULT_MESSAGE_THREAD_TIMESTAMP = ""
 	DEFAULT_MESSAGE_REPLY_BROADCAST  = false
 	DEFAULT_MESSAGE_ASUSER           = false
 	DEFAULT_MESSAGE_PARSE            = ""
+	DEFAULT_MESSAGE_THREAD_TIMESTAMP = ""
 	DEFAULT_MESSAGE_LINK_NAMES       = 0
 	DEFAULT_MESSAGE_UNFURL_LINKS     = false
 	DEFAULT_MESSAGE_UNFURL_MEDIA     = true
@@ -24,16 +23,26 @@ const (
 )
 
 type chatResponseFull struct {
-	Channel   string `json:"channel"`
-	Timestamp string `json:"ts"`
-	Text      string `json:"text"`
+	Channel          string `json:"channel"`
+	Timestamp        string `json:"ts"`         //Regualr message timestamp
+	MessageTimeStamp string `json:"message_ts"` //Ephemeral message timestamp
+	Text             string `json:"text"`
 	SlackResponse
 }
 
+// getMessageTimestamp will inspect the `chatResponseFull` to ruturn a timestamp value
+// in `chat.postMessage` its under `ts`
+// in `chat.postEphemeral` its under `message_ts`
+func (c chatResponseFull) getMessageTimestamp() string {
+	if len(c.Timestamp) > 0 {
+		return c.Timestamp
+	}
+	return c.MessageTimeStamp
+}
+
 // PostMessageParameters contains all the parameters necessary (including the optional ones) for a PostMessage() request
 type PostMessageParameters struct {
-	Text            string       `json:"text"`
-	Username        string       `json:"user_name"`
+	Username        string       `json:"username"`
 	AsUser          bool         `json:"as_user"`
 	Parse           string       `json:"parse"`
 	ThreadTimestamp string       `json:"thread_ts"`
@@ -55,18 +64,19 @@ type PostMessageParameters struct {
 // NewPostMessageParameters provides an instance of PostMessageParameters with all the sane default values set
 func NewPostMessageParameters() PostMessageParameters {
 	return PostMessageParameters{
-		Username:    DEFAULT_MESSAGE_USERNAME,
-		User:        DEFAULT_MESSAGE_USERNAME,
-		AsUser:      DEFAULT_MESSAGE_ASUSER,
-		Parse:       DEFAULT_MESSAGE_PARSE,
-		LinkNames:   DEFAULT_MESSAGE_LINK_NAMES,
-		Attachments: nil,
-		UnfurlLinks: DEFAULT_MESSAGE_UNFURL_LINKS,
-		UnfurlMedia: DEFAULT_MESSAGE_UNFURL_MEDIA,
-		IconURL:     DEFAULT_MESSAGE_ICON_URL,
-		IconEmoji:   DEFAULT_MESSAGE_ICON_EMOJI,
-		Markdown:    DEFAULT_MESSAGE_MARKDOWN,
-		EscapeText:  DEFAULT_MESSAGE_ESCAPE_TEXT,
+		Username:        DEFAULT_MESSAGE_USERNAME,
+		User:            DEFAULT_MESSAGE_USERNAME,
+		AsUser:          DEFAULT_MESSAGE_ASUSER,
+		Parse:           DEFAULT_MESSAGE_PARSE,
+		ThreadTimestamp: DEFAULT_MESSAGE_THREAD_TIMESTAMP,
+		LinkNames:       DEFAULT_MESSAGE_LINK_NAMES,
+		Attachments:     nil,
+		UnfurlLinks:     DEFAULT_MESSAGE_UNFURL_LINKS,
+		UnfurlMedia:     DEFAULT_MESSAGE_UNFURL_MEDIA,
+		IconURL:         DEFAULT_MESSAGE_ICON_URL,
+		IconEmoji:       DEFAULT_MESSAGE_ICON_EMOJI,
+		Markdown:        DEFAULT_MESSAGE_MARKDOWN,
+		EscapeText:      DEFAULT_MESSAGE_ESCAPE_TEXT,
 	}
 }
 
@@ -112,11 +122,10 @@ func (api *Client) PostMessageContext(ctx context.Context, channel, text string,
 // PostEphemeral sends an ephemeral message to a user in a channel.
 // Message is escaped by default according to https://api.slack.com/docs/formatting
 // Use http://davestevens.github.io/slack-message-builder/ to help crafting your message.
-func (api *Client) PostEphemeral(channel, userID string, options ...MsgOption) (string, error) {
-	options = append(options, MsgOptionPostEphemeral())
+func (api *Client) PostEphemeral(channelID, userID string, options ...MsgOption) (string, error) {
 	return api.PostEphemeralContext(
 		context.Background(),
-		channel,
+		channelID,
 		userID,
 		options...,
 	)
@@ -124,30 +133,19 @@ func (api *Client) PostEphemeral(channel, userID string, options ...MsgOption) (
 
 // PostEphemeralContext sends an ephemeal message to a user in a channel with a custom context
 // For more details, see PostEphemeral documentation
-func (api *Client) PostEphemeralContext(ctx context.Context, channel, userID string, options ...MsgOption) (string, error) {
-	path, values, err := ApplyMsgOptions(api.config.token, channel, options...)
-	if err != nil {
-		return "", err
-	}
-
-	values.Add("user", userID)
-
-	response, err := chatRequest(ctx, path, values, api.debug)
-	if err != nil {
-		return "", err
-	}
-
-	return response.Timestamp, nil
+func (api *Client) PostEphemeralContext(ctx context.Context, channelID, userID string, options ...MsgOption) (timestamp string, err error) {
+	_, timestamp, _, err = api.SendMessageContext(ctx, channelID, append(options, MsgOptionPostEphemeral2(userID))...)
+	return timestamp, err
 }
 
 // UpdateMessage updates a message in a channel
-func (api *Client) UpdateMessage(channel, timestamp, text string) (string, string, string, error) {
-	return api.UpdateMessageContext(context.Background(), channel, timestamp, text)
+func (api *Client) UpdateMessage(channelID, timestamp, text string) (string, string, string, error) {
+	return api.UpdateMessageContext(context.Background(), channelID, timestamp, text)
 }
 
-// UpdateMessage updates a message in a channel
-func (api *Client) UpdateMessageContext(ctx context.Context, channel, timestamp, text string) (string, string, string, error) {
-	return api.SendMessageContext(ctx, channel, MsgOptionUpdate(timestamp), MsgOptionText(text, true))
+// UpdateMessageContext updates a message in a channel
+func (api *Client) UpdateMessageContext(ctx context.Context, channelID, timestamp, text string) (string, string, string, error) {
+	return api.SendMessageContext(ctx, channelID, MsgOptionUpdate(timestamp), MsgOptionText(text, true))
 }
 
 // SendMessage more flexible method for configuring messages.
@@ -156,22 +154,30 @@ func (api *Client) SendMessage(channel string, options ...MsgOption) (string, st
 }
 
 // SendMessageContext more flexible method for configuring messages with a custom context.
-func (api *Client) SendMessageContext(ctx context.Context, channel string, options ...MsgOption) (string, string, string, error) {
-	channel, values, err := ApplyMsgOptions(api.config.token, channel, options...)
-	if err != nil {
+func (api *Client) SendMessageContext(ctx context.Context, channelID string, options ...MsgOption) (channel string, timestamp string, text string, err error) {
+	var (
+		config   sendConfig
+		response chatResponseFull
+	)
+
+	if config, err = applyMsgOptions(api.token, channelID, options...); err != nil {
 		return "", "", "", err
 	}
 
-	response, err := chatRequest(ctx, channel, values, api.debug)
-	if err != nil {
+	if err = postSlackMethod(ctx, api.httpclient, string(config.mode), config.values, &response, api.debug); err != nil {
 		return "", "", "", err
 	}
 
-	return response.Channel, response.Timestamp, response.Text, nil
+	return response.Channel, response.getMessageTimestamp(), response.Text, response.Err()
 }
 
 // ApplyMsgOptions utility function for debugging/testing chat requests.
 func ApplyMsgOptions(token, channel string, options ...MsgOption) (string, url.Values, error) {
+	config, err := applyMsgOptions(token, channel, options...)
+	return string(config.mode), config.values, err
+}
+
+func applyMsgOptions(token, channel string, options ...MsgOption) (sendConfig, error) {
 	config := sendConfig{
 		mode: chatPostMessage,
 		values: url.Values{
@@ -182,11 +188,11 @@ func ApplyMsgOptions(token, channel string, options ...MsgOption) (string, url.V
 
 	for _, opt := range options {
 		if err := opt(&config); err != nil {
-			return string(config.mode), config.values, err
+			return config, err
 		}
 	}
 
-	return string(config.mode), config.values, nil
+	return config, nil
 }
 
 func escapeMessage(message string) string {
@@ -194,18 +200,6 @@ func escapeMessage(message string) string {
 	return replacer.Replace(message)
 }
 
-func chatRequest(ctx context.Context, path string, values url.Values, debug bool) (*chatResponseFull, error) {
-	response := &chatResponseFull{}
-	err := post(ctx, path, values, response, debug)
-	if err != nil {
-		return nil, err
-	}
-	if !response.Ok {
-		return nil, errors.New(response.Error)
-	}
-	return response, nil
-}
-
 type sendMode string
 
 const (
@@ -213,6 +207,7 @@ const (
 	chatPostMessage   sendMode = "chat.postMessage"
 	chatDelete        sendMode = "chat.delete"
 	chatPostEphemeral sendMode = "chat.postEphemeral"
+	chatMeMessage     sendMode = "chat.meMessage"
 )
 
 type sendConfig struct {
@@ -232,7 +227,8 @@ func MsgOptionPost() MsgOption {
 	}
 }
 
-// MsgOptionPostEphemeral posts an ephemeral message
+// MsgOptionPostEphemeral - DEPRECATED: use MsgOptionPostEphemeral2
+// posts an ephemeral message.
 func MsgOptionPostEphemeral() MsgOption {
 	return func(config *sendConfig) error {
 		config.mode = chatPostEphemeral
@@ -241,6 +237,25 @@ func MsgOptionPostEphemeral() MsgOption {
 	}
 }
 
+// MsgOptionPostEphemeral2 - posts an ephemeral message to the provided user.
+func MsgOptionPostEphemeral2(userID string) MsgOption {
+	return func(config *sendConfig) error {
+		config.mode = chatPostEphemeral
+		MsgOptionUser(userID)(config)
+		config.values.Del("ts")
+
+		return nil
+	}
+}
+
+// MsgOptionMeMessage posts a "me message" type from the calling user
+func MsgOptionMeMessage() MsgOption {
+	return func(config *sendConfig) error {
+		config.mode = chatMeMessage
+		return nil
+	}
+}
+
 // MsgOptionUpdate updates a message based on the timestamp.
 func MsgOptionUpdate(timestamp string) MsgOption {
 	return func(config *sendConfig) error {
@@ -269,6 +284,14 @@ func MsgOptionAsUser(b bool) MsgOption {
 	}
 }
 
+// MsgOptionUser set the user for the message.
+func MsgOptionUser(userID string) MsgOption {
+	return func(config *sendConfig) error {
+		config.values.Set("user", userID)
+		return nil
+	}
+}
+
 // MsgOptionText provide the text for the message, optionally escape the provided
 // text.
 func MsgOptionText(text string, escape bool) MsgOption {
@@ -304,6 +327,14 @@ func MsgOptionEnableLinkUnfurl() MsgOption {
 	}
 }
 
+// MsgOptionDisableLinkUnfurl disables link unfurling
+func MsgOptionDisableLinkUnfurl() MsgOption {
+	return func(config *sendConfig) error {
+		config.values.Set("unfurl_links", "false")
+		return nil
+	}
+}
+
 // MsgOptionDisableMediaUnfurl disables media unfurling.
 func MsgOptionDisableMediaUnfurl() MsgOption {
 	return func(config *sendConfig) error {
@@ -320,11 +351,52 @@ func MsgOptionDisableMarkdown() MsgOption {
 	}
 }
 
+// MsgOptionTS sets the thread TS of the message to enable creating or replying to a thread
+func MsgOptionTS(ts string) MsgOption {
+	return func(config *sendConfig) error {
+		config.values.Set("thread_ts", ts)
+		return nil
+	}
+}
+
+// MsgOptionBroadcast sets reply_broadcast to true
+func MsgOptionBroadcast() MsgOption {
+	return func(config *sendConfig) error {
+		config.values.Set("reply_broadcast", "true")
+		return nil
+	}
+}
+
+// this function combines multiple options into a single option.
+func MsgOptionCompose(options ...MsgOption) MsgOption {
+	return func(c *sendConfig) error {
+		for _, opt := range options {
+			if err := opt(c); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+}
+
+func MsgOptionParse(b bool) MsgOption {
+	return func(c *sendConfig) error {
+		var v string
+		if b {
+			v = "1"
+		} else {
+			v = "0"
+		}
+		c.values.Set("parse", v)
+		return nil
+	}
+}
+
 // MsgOptionPostMessageParameters maintain backwards compatibility.
 func MsgOptionPostMessageParameters(params PostMessageParameters) MsgOption {
 	return func(config *sendConfig) error {
 		if params.Username != DEFAULT_MESSAGE_USERNAME {
-			config.values.Set("username", string(params.Username))
+			config.values.Set("username", params.Username)
 		}
 
 		// chat.postEphemeral support
@@ -336,7 +408,7 @@ func MsgOptionPostMessageParameters(params PostMessageParameters) MsgOption {
 		MsgOptionAsUser(params.AsUser)(config)
 
 		if params.Parse != DEFAULT_MESSAGE_PARSE {
-			config.values.Set("parse", string(params.Parse))
+			config.values.Set("parse", params.Parse)
 		}
 		if params.LinkNames != DEFAULT_MESSAGE_LINK_NAMES {
 			config.values.Set("link_names", "1")
diff --git a/vendor/github.com/nlopes/slack/conversation.go b/vendor/github.com/nlopes/slack/conversation.go
index 83a1d4ee..edde87a2 100644
--- a/vendor/github.com/nlopes/slack/conversation.go
+++ b/vendor/github.com/nlopes/slack/conversation.go
@@ -1,5 +1,13 @@
 package slack
 
+import (
+	"context"
+	"errors"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
 // Conversation is the foundation for IM and BaseGroupConversation
 type conversation struct {
 	ID                 string   `json:"id"`
@@ -9,6 +17,20 @@ type conversation struct {
 	Latest             *Message `json:"latest,omitempty"`
 	UnreadCount        int      `json:"unread_count,omitempty"`
 	UnreadCountDisplay int      `json:"unread_count_display,omitempty"`
+	IsGroup            bool     `json:"is_group"`
+	IsShared           bool     `json:"is_shared"`
+	IsIM               bool     `json:"is_im"`
+	IsExtShared        bool     `json:"is_ext_shared"`
+	IsOrgShared        bool     `json:"is_org_shared"`
+	IsPendingExtShared bool     `json:"is_pending_ext_shared"`
+	IsPrivate          bool     `json:"is_private"`
+	IsMpIM             bool     `json:"is_mpim"`
+	Unlinked           int      `json:"unlinked"`
+	NameNormalized     string   `json:"name_normalized"`
+	NumMembers         int      `json:"num_members"`
+	Priority           float64  `json:"priority"`
+	// TODO support pending_shared
+	// TODO support previous_names
 }
 
 // GroupConversation is the foundation for Group and Channel
@@ -35,3 +57,510 @@ type Purpose struct {
 	Creator string   `json:"creator"`
 	LastSet JSONTime `json:"last_set"`
 }
+
+type GetUsersInConversationParameters struct {
+	ChannelID string
+	Cursor    string
+	Limit     int
+}
+
+type responseMetaData struct {
+	NextCursor string `json:"next_cursor"`
+}
+
+// GetUsersInConversation returns the list of users in a conversation
+func (api *Client) GetUsersInConversation(params *GetUsersInConversationParameters) ([]string, string, error) {
+	return api.GetUsersInConversationContext(context.Background(), params)
+}
+
+// GetUsersInConversationContext returns the list of users in a conversation with a custom context
+func (api *Client) GetUsersInConversationContext(ctx context.Context, params *GetUsersInConversationParameters) ([]string, string, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {params.ChannelID},
+	}
+	if params.Cursor != "" {
+		values.Add("cursor", params.Cursor)
+	}
+	if params.Limit != 0 {
+		values.Add("limit", strconv.Itoa(params.Limit))
+	}
+	response := struct {
+		Members          []string         `json:"members"`
+		ResponseMetaData responseMetaData `json:"response_metadata"`
+		SlackResponse
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.members", values, &response, api.debug)
+	if err != nil {
+		return nil, "", err
+	}
+	if !response.Ok {
+		return nil, "", errors.New(response.Error)
+	}
+	return response.Members, response.ResponseMetaData.NextCursor, nil
+}
+
+// ArchiveConversation archives a conversation
+func (api *Client) ArchiveConversation(channelID string) error {
+	return api.ArchiveConversationContext(context.Background(), channelID)
+}
+
+// ArchiveConversationContext archives a conversation with a custom context
+func (api *Client) ArchiveConversationContext(ctx context.Context, channelID string) error {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+	}
+	response := SlackResponse{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.archive", values, &response, api.debug)
+	if err != nil {
+		return err
+	}
+
+	return response.Err()
+}
+
+// UnArchiveConversation reverses conversation archival
+func (api *Client) UnArchiveConversation(channelID string) error {
+	return api.UnArchiveConversationContext(context.Background(), channelID)
+}
+
+// UnArchiveConversationContext reverses conversation archival with a custom context
+func (api *Client) UnArchiveConversationContext(ctx context.Context, channelID string) error {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+	}
+	response := SlackResponse{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.unarchive", values, &response, api.debug)
+	if err != nil {
+		return err
+	}
+
+	return response.Err()
+}
+
+// SetTopicOfConversation sets the topic for a conversation
+func (api *Client) SetTopicOfConversation(channelID, topic string) (*Channel, error) {
+	return api.SetTopicOfConversationContext(context.Background(), channelID, topic)
+}
+
+// SetTopicOfConversationContext sets the topic for a conversation with a custom context
+func (api *Client) SetTopicOfConversationContext(ctx context.Context, channelID, topic string) (*Channel, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+		"topic":   {topic},
+	}
+	response := struct {
+		SlackResponse
+		Channel *Channel `json:"channel"`
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.setTopic", values, &response, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return response.Channel, response.Err()
+}
+
+// SetPurposeOfConversation sets the purpose for a conversation
+func (api *Client) SetPurposeOfConversation(channelID, purpose string) (*Channel, error) {
+	return api.SetPurposeOfConversationContext(context.Background(), channelID, purpose)
+}
+
+// SetPurposeOfConversationContext sets the purpose for a conversation with a custom context
+func (api *Client) SetPurposeOfConversationContext(ctx context.Context, channelID, purpose string) (*Channel, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+		"purpose": {purpose},
+	}
+	response := struct {
+		SlackResponse
+		Channel *Channel `json:"channel"`
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.setPurpose", values, &response, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return response.Channel, response.Err()
+}
+
+// RenameConversation renames a conversation
+func (api *Client) RenameConversation(channelID, channelName string) (*Channel, error) {
+	return api.RenameConversationContext(context.Background(), channelID, channelName)
+}
+
+// RenameConversationContext renames a conversation with a custom context
+func (api *Client) RenameConversationContext(ctx context.Context, channelID, channelName string) (*Channel, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+		"name":    {channelName},
+	}
+	response := struct {
+		SlackResponse
+		Channel *Channel `json:"channel"`
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.rename", values, &response, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return response.Channel, response.Err()
+}
+
+// InviteUsersToConversation invites users to a channel
+func (api *Client) InviteUsersToConversation(channelID string, users ...string) (*Channel, error) {
+	return api.InviteUsersToConversationContext(context.Background(), channelID, users...)
+}
+
+// InviteUsersToConversationContext invites users to a channel with a custom context
+func (api *Client) InviteUsersToConversationContext(ctx context.Context, channelID string, users ...string) (*Channel, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+		"users":   {strings.Join(users, ",")},
+	}
+	response := struct {
+		SlackResponse
+		Channel *Channel `json:"channel"`
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.invite", values, &response, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return response.Channel, response.Err()
+}
+
+// KickUserFromConversation removes a user from a conversation
+func (api *Client) KickUserFromConversation(channelID string, user string) error {
+	return api.KickUserFromConversationContext(context.Background(), channelID, user)
+}
+
+// KickUserFromConversationContext removes a user from a conversation with a custom context
+func (api *Client) KickUserFromConversationContext(ctx context.Context, channelID string, user string) error {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+		"user":    {user},
+	}
+	response := SlackResponse{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.kick", values, &response, api.debug)
+	if err != nil {
+		return err
+	}
+
+	return response.Err()
+}
+
+// CloseConversation closes a direct message or multi-person direct message
+func (api *Client) CloseConversation(channelID string) (noOp bool, alreadyClosed bool, err error) {
+	return api.CloseConversationContext(context.Background(), channelID)
+}
+
+// CloseConversationContext closes a direct message or multi-person direct message with a custom context
+func (api *Client) CloseConversationContext(ctx context.Context, channelID string) (noOp bool, alreadyClosed bool, err error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+	}
+	response := struct {
+		SlackResponse
+		NoOp          bool `json:"no_op"`
+		AlreadyClosed bool `json:"already_closed"`
+	}{}
+
+	err = postSlackMethod(ctx, api.httpclient, "conversations.close", values, &response, api.debug)
+	if err != nil {
+		return false, false, err
+	}
+
+	return response.NoOp, response.AlreadyClosed, response.Err()
+}
+
+// CreateConversation initiates a public or private channel-based conversation
+func (api *Client) CreateConversation(channelName string, isPrivate bool) (*Channel, error) {
+	return api.CreateConversationContext(context.Background(), channelName, isPrivate)
+}
+
+// CreateConversationContext initiates a public or private channel-based conversation with a custom context
+func (api *Client) CreateConversationContext(ctx context.Context, channelName string, isPrivate bool) (*Channel, error) {
+	values := url.Values{
+		"token":      {api.token},
+		"name":       {channelName},
+		"is_private": {strconv.FormatBool(isPrivate)},
+	}
+	response, err := channelRequest(
+		ctx, api.httpclient, "conversations.create", values, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return &response.Channel, response.Err()
+}
+
+// GetConversationInfo retrieves information about a conversation
+func (api *Client) GetConversationInfo(channelID string, includeLocale bool) (*Channel, error) {
+	return api.GetConversationInfoContext(context.Background(), channelID, includeLocale)
+}
+
+// GetConversationInfoContext retrieves information about a conversation with a custom context
+func (api *Client) GetConversationInfoContext(ctx context.Context, channelID string, includeLocale bool) (*Channel, error) {
+	values := url.Values{
+		"token":          {api.token},
+		"channel":        {channelID},
+		"include_locale": {strconv.FormatBool(includeLocale)},
+	}
+	response, err := channelRequest(
+		ctx, api.httpclient, "conversations.info", values, api.debug)
+	if err != nil {
+		return nil, err
+	}
+
+	return &response.Channel, response.Err()
+}
+
+// LeaveConversation leaves a conversation
+func (api *Client) LeaveConversation(channelID string) (bool, error) {
+	return api.LeaveConversationContext(context.Background(), channelID)
+}
+
+// LeaveConversationContext leaves a conversation with a custom context
+func (api *Client) LeaveConversationContext(ctx context.Context, channelID string) (bool, error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {channelID},
+	}
+
+	response, err := channelRequest(ctx, api.httpclient, "conversations.leave", values, api.debug)
+	if err != nil {
+		return false, err
+	}
+
+	return response.NotInChannel, err
+}
+
+type GetConversationRepliesParameters struct {
+	ChannelID string
+	Timestamp string
+	Cursor    string
+	Inclusive bool
+	Latest    string
+	Limit     int
+	Oldest    string
+}
+
+// GetConversationReplies retrieves a thread of messages posted to a conversation
+func (api *Client) GetConversationReplies(params *GetConversationRepliesParameters) (msgs []Message, hasMore bool, nextCursor string, err error) {
+	return api.GetConversationRepliesContext(context.Background(), params)
+}
+
+// GetConversationRepliesContext retrieves a thread of messages posted to a conversation with a custom context
+func (api *Client) GetConversationRepliesContext(ctx context.Context, params *GetConversationRepliesParameters) (msgs []Message, hasMore bool, nextCursor string, err error) {
+	values := url.Values{
+		"token":   {api.token},
+		"channel": {params.ChannelID},
+		"ts":      {params.Timestamp},
+	}
+	if params.Cursor != "" {
+		values.Add("cursor", params.Cursor)
+	}
+	if params.Latest != "" {
+		values.Add("latest", params.Latest)
+	}
+	if params.Limit != 0 {
+		values.Add("limit", strconv.Itoa(params.Limit))
+	}
+	if params.Oldest != "" {
+		values.Add("oldest", params.Oldest)
+	}
+	if params.Inclusive {
+		values.Add("inclusive", "1")
+	} else {
+		values.Add("inclusive", "0")
+	}
+	response := struct {
+		SlackResponse
+		HasMore          bool `json:"has_more"`
+		ResponseMetaData struct {
+			NextCursor string `json:"next_cursor"`
+		} `json:"response_metadata"`
+		Messages []Message `json:"messages"`
+	}{}
+
+	err = postSlackMethod(ctx, api.httpclient, "conversations.replies", values, &response, api.debug)
+	if err != nil {
+		return nil, false, "", err
+	}
+
+	return response.Messages, response.HasMore, response.ResponseMetaData.NextCursor, response.Err()
+}
+
+type GetConversationsParameters struct {
+	Cursor          string
+	ExcludeArchived string
+	Limit           int
+	Types           []string
+}
+
+// GetConversations returns the list of channels in a Slack team
+func (api *Client) GetConversations(params *GetConversationsParameters) (channels []Channel, nextCursor string, err error) {
+	return api.GetConversationsContext(context.Background(), params)
+}
+
+// GetConversationsContext returns the list of channels in a Slack team with a custom context
+func (api *Client) GetConversationsContext(ctx context.Context, params *GetConversationsParameters) (channels []Channel, nextCursor string, err error) {
+	values := url.Values{
+		"token":            {api.token},
+		"exclude_archived": {params.ExcludeArchived},
+	}
+	if params.Cursor != "" {
+		values.Add("cursor", params.Cursor)
+	}
+	if params.Limit != 0 {
+		values.Add("limit", strconv.Itoa(params.Limit))
+	}
+	if params.Types != nil {
+		values.Add("types", strings.Join(params.Types, ","))
+	}
+	response := struct {
+		Channels         []Channel        `json:"channels"`
+		ResponseMetaData responseMetaData `json:"response_metadata"`
+		SlackResponse
+	}{}
+	err = postSlackMethod(ctx, api.httpclient, "conversations.list", values, &response, api.debug)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return response.Channels, response.ResponseMetaData.NextCursor, response.Err()
+}
+
+type OpenConversationParameters struct {
+	ChannelID string
+	ReturnIM  bool
+	Users     []string
+}
+
+// OpenConversation opens or resumes a direct message or multi-person direct message
+func (api *Client) OpenConversation(params *OpenConversationParameters) (*Channel, bool, bool, error) {
+	return api.OpenConversationContext(context.Background(), params)
+}
+
+// OpenConversationContext opens or resumes a direct message or multi-person direct message with a custom context
+func (api *Client) OpenConversationContext(ctx context.Context, params *OpenConversationParameters) (*Channel, bool, bool, error) {
+	values := url.Values{
+		"token":     {api.token},
+		"return_im": {strconv.FormatBool(params.ReturnIM)},
+	}
+	if params.ChannelID != "" {
+		values.Add("channel", params.ChannelID)
+	}
+	if params.Users != nil {
+		values.Add("users", strings.Join(params.Users, ","))
+	}
+	response := struct {
+		Channel     *Channel `json:"channel"`
+		NoOp        bool     `json:"no_op"`
+		AlreadyOpen bool     `json:"already_open"`
+		SlackResponse
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.open", values, &response, api.debug)
+	if err != nil {
+		return nil, false, false, err
+	}
+
+	return response.Channel, response.NoOp, response.AlreadyOpen, response.Err()
+}
+
+// JoinConversation joins an existing conversation
+func (api *Client) JoinConversation(channelID string) (*Channel, string, []string, error) {
+	return api.JoinConversationContext(context.Background(), channelID)
+}
+
+// JoinConversationContext joins an existing conversation with a custom context
+func (api *Client) JoinConversationContext(ctx context.Context, channelID string) (*Channel, string, []string, error) {
+	values := url.Values{"token": {api.token}, "channel": {channelID}}
+	response := struct {
+		Channel          *Channel `json:"channel"`
+		Warning          string   `json:"warning"`
+		ResponseMetaData *struct {
+			Warnings []string `json:"warnings"`
+		} `json:"response_metadata"`
+		SlackResponse
+	}{}
+	err := postSlackMethod(ctx, api.httpclient, "conversations.join", values, &response, api.debug)
+	if err != nil {
+		return nil, "", nil, err
+	}
+	if response.Err() != nil {
+		return nil, "", nil, response.Err()
+	}
+	var warnings []string
+	if response.ResponseMetaData != nil {
+		warnings = response.ResponseMetaData.Warnings
+	}
+	return response.Channel, response.Warning, warnings, nil
+}
+
+type GetConversationHistoryParameters struct {
+	ChannelID string
+	Cursor    string
+	Inclusive bool
+	Latest    string
+	Limit     int
+	Oldest    string
+}
+
+type GetConversationHistoryResponse struct {
+	SlackResponse
+	HasMore          bool   `json:"has_more"`
+	PinCount         int    `json:"pin_count"`
+	Latest           string `json:"latest"`
+	ResponseMetaData struct {
+		NextCursor string `json:"next_cursor"`
+	} `json:"response_metadata"`
+	Messages []Message `json:"messages"`
+}
+
+// GetConversationHistory joins an existing conversation
+func (api *Client) GetConversationHistory(params *GetConversationHistoryParameters) (*GetConversationHistoryResponse, error) {
+	return api.GetConversationHistoryContext(context.Background(), params)
+}
+
+// GetConversationHistoryContext joins an existing conversation with a custom context
+func (api *Client) GetConversationHistoryContext(ctx context.Context, params *GetConversationHistoryParameters) (*GetConversationHistoryResponse, error) {
+	values := url.Values{"token": {api.token}, "channel": {params.ChannelID}}
+	if params.Cursor != "" {
+		values.Add("cursor", params.Cursor)
+	}
+	if params.Inclusive {
+		values.Add("inclusive", "1")
+	} else {
+		values.Add("inclusive", "0")
+	}
+	if params.Latest != "" {
+		values.Add("latest", params.Latest)
+	}
+	if params.Limit != 0 {
+		values.Add("limit", strconv.Itoa(params.Limit))
+	}
+	if params.Oldest != "" {
+		values.Add("oldest", params.Oldest)
+	}
+
+	response := GetConversationHistoryResponse{}
+
+	err := postSlackMethod(ctx, api.httpclient, "conversations.history", values, &response, api.debug)
+	if err != nil {
+		return nil, err
+	}
+	if !response.Ok {
+		return nil, errors.New(response.Error)
+	}
+	return &response, nil
+}
diff --git a/vendor/github.com/nlopes/slack/dialog.go b/vendor/github.com/nlopes/slack/dialog.go
new file mode 100644
index 00000000..a13e53da
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/dialog.go
@@ -0,0 +1,107 @@
+package slack
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+)
+
+type DialogTrigger struct {
+	TriggerId string `json:"trigger_id"` //Required. Must respond within 3 seconds.
+	Dialog    Dialog `json:"dialog"`     //Required.
+}
+
+type Dialog struct {
+	CallbackId     string          `json:"callback_id"`                //Required.
+	Title          string          `json:"title"`                      //Required.
+	SubmitLabel    string          `json:"submit_label,omitempty"`     //Optional. Default value is 'Submit'
+	NotifyOnCancel bool            `json:"notify_on_cancel,omitempty"` //Optional. Default value is false
+	Elements       []DialogElement `json:"elements"`                   //Required.
+}
+
+type DialogElement interface{}
+
+type DialogTextElement struct {
+	Label       string `json:"label"`                 //Required.
+	Name        string `json:"name"`                  //Required.
+	Type        string `json:"type"`                  //Required. Allowed values: "text", "textarea", "select".
+	Placeholder string `json:"placeholder,omitempty"` //Optional.
+	Optional    bool   `json:"optional,omitempty"`    //Optional. Default value is false
+	Value       string `json:"value,omitempty"`       //Optional.
+	MaxLength   int    `json:"max_length,omitempty"`  //Optional.
+	MinLength   int    `json:"min_length,omitempty"`  //Optional,. Default value is 0
+	Hint        string `json:"hint,omitempty"`        //Optional.
+	Subtype     string `json:"subtype,omitempty"`     //Optional. Allowed values: "email", "number", "tel", "url".
+}
+
+type DialogSelectElement struct {
+	Label           string                `json:"label"`                      //Required.
+	Name            string                `json:"name"`                       //Required.
+	Type            string                `json:"type"`                       //Required. Allowed values: "text", "textarea", "select".
+	Placeholder     string                `json:"placeholder,omitempty"`      //Optional.
+	Optional        bool                  `json:"optional,omitempty"`         //Optional. Default value is false
+	Value           string                `json:"value,omitempty"`            //Optional.
+	DataSource      string                `json:"data_source,omitempty"`      //Optional. Allowed values: "users", "channels", "conversations", "external".
+	SelectedOptions string                `json:"selected_options,omitempty"` //Optional. Default value for "external" only
+	Options         []DialogElementOption `json:"options,omitempty"`          //One of options or option_groups is required.
+	OptionGroups    []DialogElementOption `json:"option_groups,omitempty"`    //Provide up to 100 options.
+}
+
+type DialogElementOption struct {
+	Label string `json:"label"` //Required.
+	Value string `json:"value"` //Required.
+}
+
+// DialogCallback is sent from Slack when a user submits a form from within a dialog
+type DialogCallback struct {
+	Type        string            `json:"type"`
+	CallbackID  string            `json:"callback_id"`
+	Team        Team              `json:"team"`
+	Channel     Channel           `json:"channel"`
+	User        User              `json:"user"`
+	ActionTs    string            `json:"action_ts"`
+	Token       string            `json:"token"`
+	ResponseURL string            `json:"response_url"`
+	Submission  map[string]string `json:"submission"`
+}
+
+// DialogSuggestionCallback is sent from Slack when a user types in a select field with an external data source
+type DialogSuggestionCallback struct {
+	Type        string  `json:"type"`
+	Token       string  `json:"token"`
+	ActionTs    string  `json:"action_ts"`
+	Team        Team    `json:"team"`
+	User        User    `json:"user"`
+	Channel     Channel `json:"channel"`
+	ElementName string  `json:"name"`
+	Value       string  `json:"value"`
+	CallbackID  string  `json:"callback_id"`
+}
+
+// OpenDialog opens a dialog window where the triggerId originated from
+func (api *Client) OpenDialog(triggerId string, dialog Dialog) (err error) {
+	return api.OpenDialogContext(context.Background(), triggerId, dialog)
+}
+
+// OpenDialogContext opens a dialog window where the triggerId originated from with a custom context
+func (api *Client) OpenDialogContext(ctx context.Context, triggerId string, dialog Dialog) (err error) {
+	if triggerId == "" {
+		return errors.New("received empty parameters")
+	}
+
+	resp := DialogTrigger{
+		TriggerId: triggerId,
+		Dialog:    dialog,
+	}
+	jsonResp, err := json.Marshal(resp)
+	if err != nil {
+		return err
+	}
+	response := &SlackResponse{}
+	endpoint := SLACK_API + "dialog.open"
+	if err := postJSON(ctx, api.httpclient, endpoint, api.token, jsonResp, response, api.debug); err != nil {
+		return err
+	}
+
+	return response.Err()
+}
diff --git a/vendor/github.com/nlopes/slack/dnd.go b/vendor/github.com/nlopes/slack/dnd.go
index 4f1b3228..26d36d6a 100644
--- a/vendor/github.com/nlopes/slack/dnd.go
+++ b/vendor/github.com/nlopes/slack/dnd.go
@@ -36,9 +36,9 @@ type dndTeamInfoResponse struct {
 	SlackResponse
 }
 
-func dndRequest(ctx context.Context, path string, values url.Values, debug bool) (*dndResponseFull, error) {
+func dndRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*dndResponseFull, error) {
 	response := &dndResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -56,17 +56,16 @@ func (api *Client) EndDND() error {
 // EndDNDContext ends the user's scheduled Do Not Disturb session with a custom context
 func (api *Client) EndDNDContext(ctx context.Context) error {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 
 	response := &SlackResponse{}
-	if err := post(ctx, "dnd.endDnd", values, response, api.debug); err != nil {
+
+	if err := postSlackMethod(ctx, api.httpclient, "dnd.endDnd", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // EndSnooze ends the current user's snooze mode
@@ -77,10 +76,10 @@ func (api *Client) EndSnooze() (*DNDStatus, error) {
 // EndSnoozeContext ends the current user's snooze mode with a custom context
 func (api *Client) EndSnoozeContext(ctx context.Context) (*DNDStatus, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 
-	response, err := dndRequest(ctx, "dnd.endSnooze", values, api.debug)
+	response, err := dndRequest(ctx, api.httpclient, "dnd.endSnooze", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -95,12 +94,13 @@ func (api *Client) GetDNDInfo(user *string) (*DNDStatus, error) {
 // GetDNDInfoContext provides information about a user's current Do Not Disturb settings with a custom context.
 func (api *Client) GetDNDInfoContext(ctx context.Context, user *string) (*DNDStatus, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if user != nil {
 		values.Set("user", *user)
 	}
-	response, err := dndRequest(ctx, "dnd.info", values, api.debug)
+
+	response, err := dndRequest(ctx, api.httpclient, "dnd.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -115,11 +115,12 @@ func (api *Client) GetDNDTeamInfo(users []string) (map[string]DNDStatus, error)
 // GetDNDTeamInfoContext provides information about a user's current Do Not Disturb settings with a custom context.
 func (api *Client) GetDNDTeamInfoContext(ctx context.Context, users []string) (map[string]DNDStatus, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"users": {strings.Join(users, ",")},
 	}
 	response := &dndTeamInfoResponse{}
-	if err := post(ctx, "dnd.teamInfo", values, response, api.debug); err != nil {
+
+	if err := postSlackMethod(ctx, api.httpclient, "dnd.teamInfo", values, response, api.debug); err != nil {
 		return nil, err
 	}
 	if !response.Ok {
@@ -139,10 +140,11 @@ func (api *Client) SetSnooze(minutes int) (*DNDStatus, error) {
 // For more information see the SetSnooze docs
 func (api *Client) SetSnoozeContext(ctx context.Context, minutes int) (*DNDStatus, error) {
 	values := url.Values{
-		"token":       {api.config.token},
+		"token":       {api.token},
 		"num_minutes": {strconv.Itoa(minutes)},
 	}
-	response, err := dndRequest(ctx, "dnd.setSnooze", values, api.debug)
+
+	response, err := dndRequest(ctx, api.httpclient, "dnd.setSnooze", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/emoji.go b/vendor/github.com/nlopes/slack/emoji.go
index 5da9da41..fe2945c4 100644
--- a/vendor/github.com/nlopes/slack/emoji.go
+++ b/vendor/github.com/nlopes/slack/emoji.go
@@ -19,10 +19,11 @@ func (api *Client) GetEmoji() (map[string]string, error) {
 // GetEmojiContext retrieves all the emojis with a custom context
 func (api *Client) GetEmojiContext(ctx context.Context) (map[string]string, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	response := &emojiResponseFull{}
-	err := post(ctx, "emoji.list", values, response, api.debug)
+
+	err := postSlackMethod(ctx, api.httpclient, "emoji.list", values, response, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/files.go b/vendor/github.com/nlopes/slack/files.go
index 68941422..2381ec3c 100644
--- a/vendor/github.com/nlopes/slack/files.go
+++ b/vendor/github.com/nlopes/slack/files.go
@@ -136,9 +136,9 @@ func NewGetFilesParameters() GetFilesParameters {
 	}
 }
 
-func fileRequest(ctx context.Context, path string, values url.Values, debug bool) (*fileResponseFull, error) {
+func fileRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*fileResponseFull, error) {
 	response := &fileResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postForm(ctx, client, SLACK_API+path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -156,12 +156,13 @@ func (api *Client) GetFileInfo(fileID string, count, page int) (*File, []Comment
 // GetFileInfoContext retrieves a file and related comments with a custom context
 func (api *Client) GetFileInfoContext(ctx context.Context, fileID string, count, page int) (*File, []Comment, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"file":  {fileID},
 		"count": {strconv.Itoa(count)},
 		"page":  {strconv.Itoa(page)},
 	}
-	response, err := fileRequest(ctx, "files.info", values, api.debug)
+
+	response, err := fileRequest(ctx, api.httpclient, "files.info", values, api.debug)
 	if err != nil {
 		return nil, nil, nil, err
 	}
@@ -176,7 +177,7 @@ func (api *Client) GetFiles(params GetFilesParameters) ([]File, *Paging, error)
 // GetFilesContext retrieves all files according to the parameters given with a custom context
 func (api *Client) GetFilesContext(ctx context.Context, params GetFilesParameters) ([]File, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.User != DEFAULT_FILES_USER {
 		values.Add("user", params.User)
@@ -199,7 +200,8 @@ func (api *Client) GetFilesContext(ctx context.Context, params GetFilesParameter
 	if params.Page != DEFAULT_FILES_PAGE {
 		values.Add("page", strconv.Itoa(params.Page))
 	}
-	response, err := fileRequest(ctx, "files.list", values, api.debug)
+
+	response, err := fileRequest(ctx, api.httpclient, "files.list", values, api.debug)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -221,7 +223,7 @@ func (api *Client) UploadFileContext(ctx context.Context, params FileUploadParam
 	}
 	response := &fileResponseFull{}
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.Filetype != "" {
 		values.Add("filetype", params.Filetype)
@@ -240,11 +242,11 @@ func (api *Client) UploadFileContext(ctx context.Context, params FileUploadParam
 	}
 	if params.Content != "" {
 		values.Add("content", params.Content)
-		err = post(ctx, "files.upload", values, response, api.debug)
+		err = postForm(ctx, api.httpclient, SLACK_API+"files.upload", values, response, api.debug)
 	} else if params.File != "" {
-		err = postLocalWithMultipartResponse(ctx, "files.upload", params.File, "file", values, response, api.debug)
+		err = postLocalWithMultipartResponse(ctx, api.httpclient, "files.upload", params.File, "file", values, response, api.debug)
 	} else if params.Reader != nil {
-		err = postWithMultipartResponse(ctx, "files.upload", params.Filename, "file", values, params.Reader, response, api.debug)
+		err = postWithMultipartResponse(ctx, api.httpclient, "files.upload", params.Filename, "file", values, params.Reader, response, api.debug)
 	}
 	if err != nil {
 		return nil, err
@@ -255,20 +257,40 @@ func (api *Client) UploadFileContext(ctx context.Context, params FileUploadParam
 	return &response.File, nil
 }
 
+// DeleteFileComment deletes a file's comment
+func (api *Client) DeleteFileComment(commentID, fileID string) error {
+	return api.DeleteFileCommentContext(context.Background(), fileID, commentID)
+}
+
+// DeleteFileCommentContext deletes a file's comment with a custom context
+func (api *Client) DeleteFileCommentContext(ctx context.Context, fileID, commentID string) (err error) {
+	if fileID == "" || commentID == "" {
+		return errors.New("received empty parameters")
+	}
+
+	values := url.Values{
+		"token": {api.token},
+		"file":  {fileID},
+		"id":    {commentID},
+	}
+	_, err = fileRequest(ctx, api.httpclient, "files.comments.delete", values, api.debug)
+	return err
+}
+
 // DeleteFile deletes a file
 func (api *Client) DeleteFile(fileID string) error {
 	return api.DeleteFileContext(context.Background(), fileID)
 }
 
 // DeleteFileContext deletes a file with a custom context
-func (api *Client) DeleteFileContext(ctx context.Context, fileID string) error {
+func (api *Client) DeleteFileContext(ctx context.Context, fileID string) (err error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"file":  {fileID},
 	}
-	_, err := fileRequest(ctx, "files.delete", values, api.debug)
-	return err
 
+	_, err = fileRequest(ctx, api.httpclient, "files.delete", values, api.debug)
+	return err
 }
 
 // RevokeFilePublicURL disables public/external sharing for a file
@@ -279,10 +301,11 @@ func (api *Client) RevokeFilePublicURL(fileID string) (*File, error) {
 // RevokeFilePublicURLContext disables public/external sharing for a file with a custom context
 func (api *Client) RevokeFilePublicURLContext(ctx context.Context, fileID string) (*File, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"file":  {fileID},
 	}
-	response, err := fileRequest(ctx, "files.revokePublicURL", values, api.debug)
+
+	response, err := fileRequest(ctx, api.httpclient, "files.revokePublicURL", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -297,10 +320,11 @@ func (api *Client) ShareFilePublicURL(fileID string) (*File, []Comment, *Paging,
 // ShareFilePublicURLContext enabled public/external sharing for a file with a custom context
 func (api *Client) ShareFilePublicURLContext(ctx context.Context, fileID string) (*File, []Comment, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"file":  {fileID},
 	}
-	response, err := fileRequest(ctx, "files.sharedPublicURL", values, api.debug)
+
+	response, err := fileRequest(ctx, api.httpclient, "files.sharedPublicURL", values, api.debug)
 	if err != nil {
 		return nil, nil, nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/groups.go b/vendor/github.com/nlopes/slack/groups.go
index d7f39144..67e78e99 100644
--- a/vendor/github.com/nlopes/slack/groups.go
+++ b/vendor/github.com/nlopes/slack/groups.go
@@ -28,9 +28,9 @@ type groupResponseFull struct {
 	SlackResponse
 }
 
-func groupRequest(ctx context.Context, path string, values url.Values, debug bool) (*groupResponseFull, error) {
+func groupRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*groupResponseFull, error) {
 	response := &groupResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postForm(ctx, client, SLACK_API+path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -45,17 +45,15 @@ func (api *Client) ArchiveGroup(group string) error {
 	return api.ArchiveGroupContext(context.Background(), group)
 }
 
-// ArchiveGroup archives a private group
+// ArchiveGroupContext archives a private group
 func (api *Client) ArchiveGroupContext(ctx context.Context, group string) error {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	_, err := groupRequest(ctx, "groups.archive", values, api.debug)
-	if err != nil {
-		return err
-	}
-	return nil
+
+	_, err := groupRequest(ctx, api.httpclient, "groups.archive", values, api.debug)
+	return err
 }
 
 // UnarchiveGroup unarchives a private group
@@ -63,17 +61,15 @@ func (api *Client) UnarchiveGroup(group string) error {
 	return api.UnarchiveGroupContext(context.Background(), group)
 }
 
-// UnarchiveGroup unarchives a private group
+// UnarchiveGroupContext unarchives a private group
 func (api *Client) UnarchiveGroupContext(ctx context.Context, group string) error {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	_, err := groupRequest(ctx, "groups.unarchive", values, api.debug)
-	if err != nil {
-		return err
-	}
-	return nil
+
+	_, err := groupRequest(ctx, api.httpclient, "groups.unarchive", values, api.debug)
+	return err
 }
 
 // CreateGroup creates a private group
@@ -81,13 +77,14 @@ func (api *Client) CreateGroup(group string) (*Group, error) {
 	return api.CreateGroupContext(context.Background(), group)
 }
 
-// CreateGroup creates a private group
+// CreateGroupContext creates a private group
 func (api *Client) CreateGroupContext(ctx context.Context, group string) (*Group, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"name":  {group},
 	}
-	response, err := groupRequest(ctx, "groups.create", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.create", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -104,14 +101,15 @@ func (api *Client) CreateChildGroup(group string) (*Group, error) {
 	return api.CreateChildGroupContext(context.Background(), group)
 }
 
-// CreateChildGroup creates a new private group archiving the old one with a custom context
+// CreateChildGroupContext creates a new private group archiving the old one with a custom context
 // For more information see CreateChildGroup
 func (api *Client) CreateChildGroupContext(ctx context.Context, group string) (*Group, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	response, err := groupRequest(ctx, "groups.createChild", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.createChild", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -126,10 +124,11 @@ func (api *Client) CloseGroup(group string) (bool, bool, error) {
 // CloseGroupContext closes a private group with a custom context
 func (api *Client) CloseGroupContext(ctx context.Context, group string) (bool, bool, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	response, err := imRequest(ctx, "groups.close", values, api.debug)
+
+	response, err := imRequest(ctx, api.httpclient, "groups.close", values, api.debug)
 	if err != nil {
 		return false, false, err
 	}
@@ -144,7 +143,7 @@ func (api *Client) GetGroupHistory(group string, params HistoryParameters) (*His
 // GetGroupHistoryContext fetches all the history for a private group with a custom context
 func (api *Client) GetGroupHistoryContext(ctx context.Context, group string, params HistoryParameters) (*History, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
 	if params.Latest != DEFAULT_HISTORY_LATEST {
@@ -170,7 +169,8 @@ func (api *Client) GetGroupHistoryContext(ctx context.Context, group string, par
 			values.Add("unreads", "0")
 		}
 	}
-	response, err := groupRequest(ctx, "groups.history", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.history", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -185,11 +185,12 @@ func (api *Client) InviteUserToGroup(group, user string) (*Group, bool, error) {
 // InviteUserToGroupContext invites a specific user to a private group with a custom context
 func (api *Client) InviteUserToGroupContext(ctx context.Context, group, user string) (*Group, bool, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"user":    {user},
 	}
-	response, err := groupRequest(ctx, "groups.invite", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.invite", values, api.debug)
 	if err != nil {
 		return nil, false, err
 	}
@@ -202,12 +203,13 @@ func (api *Client) LeaveGroup(group string) error {
 }
 
 // LeaveGroupContext makes authenticated user leave the group with a custom context
-func (api *Client) LeaveGroupContext(ctx context.Context, group string) error {
+func (api *Client) LeaveGroupContext(ctx context.Context, group string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	_, err := groupRequest(ctx, "groups.leave", values, api.debug)
+
+	_, err = groupRequest(ctx, api.httpclient, "groups.leave", values, api.debug)
 	return err
 }
 
@@ -217,13 +219,14 @@ func (api *Client) KickUserFromGroup(group, user string) error {
 }
 
 // KickUserFromGroupContext kicks a user from a group with a custom context
-func (api *Client) KickUserFromGroupContext(ctx context.Context, group, user string) error {
+func (api *Client) KickUserFromGroupContext(ctx context.Context, group, user string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"user":    {user},
 	}
-	_, err := groupRequest(ctx, "groups.kick", values, api.debug)
+
+	_, err = groupRequest(ctx, api.httpclient, "groups.kick", values, api.debug)
 	return err
 }
 
@@ -235,12 +238,13 @@ func (api *Client) GetGroups(excludeArchived bool) ([]Group, error) {
 // GetGroupsContext retrieves all groups with a custom context
 func (api *Client) GetGroupsContext(ctx context.Context, excludeArchived bool) ([]Group, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if excludeArchived {
 		values.Add("exclude_archived", "1")
 	}
-	response, err := groupRequest(ctx, "groups.list", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.list", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -255,10 +259,11 @@ func (api *Client) GetGroupInfo(group string) (*Group, error) {
 // GetGroupInfoContext retrieves the given group with a custom context
 func (api *Client) GetGroupInfoContext(ctx context.Context, group string) (*Group, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	response, err := groupRequest(ctx, "groups.info", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -276,13 +281,14 @@ func (api *Client) SetGroupReadMark(group, ts string) error {
 
 // SetGroupReadMarkContext sets the read mark on a private group with a custom context
 // For more details see SetGroupReadMark
-func (api *Client) SetGroupReadMarkContext(ctx context.Context, group, ts string) error {
+func (api *Client) SetGroupReadMarkContext(ctx context.Context, group, ts string) (err error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"ts":      {ts},
 	}
-	_, err := groupRequest(ctx, "groups.mark", values, api.debug)
+
+	_, err = groupRequest(ctx, api.httpclient, "groups.mark", values, api.debug)
 	return err
 }
 
@@ -294,10 +300,11 @@ func (api *Client) OpenGroup(group string) (bool, bool, error) {
 // OpenGroupContext opens a private group with a custom context
 func (api *Client) OpenGroupContext(ctx context.Context, group string) (bool, bool, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 	}
-	response, err := groupRequest(ctx, "groups.open", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.open", values, api.debug)
 	if err != nil {
 		return false, false, err
 	}
@@ -314,13 +321,14 @@ func (api *Client) RenameGroup(group, name string) (*Channel, error) {
 // RenameGroupContext renames a group with a custom context
 func (api *Client) RenameGroupContext(ctx context.Context, group, name string) (*Channel, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"name":    {name},
 	}
+
 	// XXX: the created entry in this call returns a string instead of a number
 	// so I may have to do some workaround to solve it.
-	response, err := groupRequest(ctx, "groups.rename", values, api.debug)
+	response, err := groupRequest(ctx, api.httpclient, "groups.rename", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -335,11 +343,12 @@ func (api *Client) SetGroupPurpose(group, purpose string) (string, error) {
 // SetGroupPurposeContext sets the group purpose with a custom context
 func (api *Client) SetGroupPurposeContext(ctx context.Context, group, purpose string) (string, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"purpose": {purpose},
 	}
-	response, err := groupRequest(ctx, "groups.setPurpose", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.setPurpose", values, api.debug)
 	if err != nil {
 		return "", err
 	}
@@ -354,11 +363,12 @@ func (api *Client) SetGroupTopic(group, topic string) (string, error) {
 // SetGroupTopicContext sets the group topic with a custom context
 func (api *Client) SetGroupTopicContext(ctx context.Context, group, topic string) (string, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {group},
 		"topic":   {topic},
 	}
-	response, err := groupRequest(ctx, "groups.setTopic", values, api.debug)
+
+	response, err := groupRequest(ctx, api.httpclient, "groups.setTopic", values, api.debug)
 	if err != nil {
 		return "", err
 	}
diff --git a/vendor/github.com/nlopes/slack/im.go b/vendor/github.com/nlopes/slack/im.go
index 0cbc8d34..fa8b0959 100644
--- a/vendor/github.com/nlopes/slack/im.go
+++ b/vendor/github.com/nlopes/slack/im.go
@@ -29,9 +29,9 @@ type IM struct {
 	IsUserDeleted bool   `json:"is_user_deleted"`
 }
 
-func imRequest(ctx context.Context, path string, values url.Values, debug bool) (*imResponseFull, error) {
+func imRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*imResponseFull, error) {
 	response := &imResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -49,10 +49,11 @@ func (api *Client) CloseIMChannel(channel string) (bool, bool, error) {
 // CloseIMChannelContext closes the direct message channel with a custom context
 func (api *Client) CloseIMChannelContext(ctx context.Context, channel string) (bool, bool, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channel},
 	}
-	response, err := imRequest(ctx, "im.close", values, api.debug)
+
+	response, err := imRequest(ctx, api.httpclient, "im.close", values, api.debug)
 	if err != nil {
 		return false, false, err
 	}
@@ -69,10 +70,11 @@ func (api *Client) OpenIMChannel(user string) (bool, bool, string, error) {
 // Returns some status and the channel ID
 func (api *Client) OpenIMChannelContext(ctx context.Context, user string) (bool, bool, string, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"user":  {user},
 	}
-	response, err := imRequest(ctx, "im.open", values, api.debug)
+
+	response, err := imRequest(ctx, api.httpclient, "im.open", values, api.debug)
 	if err != nil {
 		return false, false, "", err
 	}
@@ -85,17 +87,15 @@ func (api *Client) MarkIMChannel(channel, ts string) (err error) {
 }
 
 // MarkIMChannelContext sets the read mark of a direct message channel to a specific point with a custom context
-func (api *Client) MarkIMChannelContext(ctx context.Context, channel, ts string) (err error) {
+func (api *Client) MarkIMChannelContext(ctx context.Context, channel, ts string) error {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channel},
 		"ts":      {ts},
 	}
-	_, err = imRequest(ctx, "im.mark", values, api.debug)
-	if err != nil {
-		return err
-	}
-	return
+
+	_, err := imRequest(ctx, api.httpclient, "im.mark", values, api.debug)
+	return err
 }
 
 // GetIMHistory retrieves the direct message channel history
@@ -106,7 +106,7 @@ func (api *Client) GetIMHistory(channel string, params HistoryParameters) (*Hist
 // GetIMHistoryContext retrieves the direct message channel history with a custom context
 func (api *Client) GetIMHistoryContext(ctx context.Context, channel string, params HistoryParameters) (*History, error) {
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"channel": {channel},
 	}
 	if params.Latest != DEFAULT_HISTORY_LATEST {
@@ -132,7 +132,8 @@ func (api *Client) GetIMHistoryContext(ctx context.Context, channel string, para
 			values.Add("unreads", "0")
 		}
 	}
-	response, err := imRequest(ctx, "im.history", values, api.debug)
+
+	response, err := imRequest(ctx, api.httpclient, "im.history", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -147,9 +148,10 @@ func (api *Client) GetIMChannels() ([]IM, error) {
 // GetIMChannelsContext returns the list of direct message channels with a custom context
 func (api *Client) GetIMChannelsContext(ctx context.Context) ([]IM, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
-	response, err := imRequest(ctx, "im.list", values, api.debug)
+
+	response, err := imRequest(ctx, api.httpclient, "im.list", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/info.go b/vendor/github.com/nlopes/slack/info.go
index 49db5327..db8534c7 100644
--- a/vendor/github.com/nlopes/slack/info.go
+++ b/vendor/github.com/nlopes/slack/info.go
@@ -1,7 +1,9 @@
 package slack
 
 import (
+	"bytes"
 	"fmt"
+	"strconv"
 	"time"
 )
 
@@ -127,6 +129,19 @@ func (t JSONTime) Time() time.Time {
 	return time.Unix(int64(t), 0)
 }
 
+// UnmarshalJSON will unmarshal both string and int JSON values
+func (t *JSONTime) UnmarshalJSON(buf []byte) error {
+	s := bytes.Trim(buf, `"`)
+
+	v, err := strconv.Atoi(string(s))
+	if err != nil {
+		return err
+	}
+
+	*t = JSONTime(int64(v))
+	return nil
+}
+
 // Team contains details about a team
 type Team struct {
 	ID     string `json:"id"`
@@ -156,7 +171,7 @@ type Info struct {
 
 type infoResponseFull struct {
 	Info
-	WebResponse
+	SlackResponse
 }
 
 // GetBotByID returns a bot given a bot id
diff --git a/vendor/github.com/nlopes/slack/logger.go b/vendor/github.com/nlopes/slack/logger.go
new file mode 100644
index 00000000..501d1672
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/logger.go
@@ -0,0 +1,53 @@
+package slack
+
+import (
+	"fmt"
+	"sync"
+)
+
+// SetLogger let's library users supply a logger, so that api debugging
+// can be logged along with the application's debugging info.
+func SetLogger(l logProvider) {
+	loggerMutex.Lock()
+	logger = ilogger{logProvider: l}
+	loggerMutex.Unlock()
+}
+
+var (
+	loggerMutex = new(sync.Mutex)
+	logger      logInternal // A logger that can be set by consumers
+)
+
+// logProvider is a logger interface compatible with both stdlib and some
+// 3rd party loggers such as logrus.
+type logProvider interface {
+	Output(int, string) error
+}
+
+// logInternal represents the internal logging api we use.
+type logInternal interface {
+	Print(...interface{})
+	Printf(string, ...interface{})
+	Println(...interface{})
+	Output(int, string) error
+}
+
+// ilogger implements the additional methods used by our internal logging.
+type ilogger struct {
+	logProvider
+}
+
+// Println replicates the behaviour of the standard logger.
+func (t ilogger) Println(v ...interface{}) {
+	t.Output(2, fmt.Sprintln(v...))
+}
+
+// Printf replicates the behaviour of the standard logger.
+func (t ilogger) Printf(format string, v ...interface{}) {
+	t.Output(2, fmt.Sprintf(format, v...))
+}
+
+// Print replicates the behaviour of the standard logger.
+func (t ilogger) Print(v ...interface{}) {
+	t.Output(2, fmt.Sprint(v...))
+}
diff --git a/vendor/github.com/nlopes/slack/messages.go b/vendor/github.com/nlopes/slack/messages.go
index cdb13098..6551dd4f 100644
--- a/vendor/github.com/nlopes/slack/messages.go
+++ b/vendor/github.com/nlopes/slack/messages.go
@@ -2,12 +2,13 @@ package slack
 
 // OutgoingMessage is used for the realtime API, and seems incomplete.
 type OutgoingMessage struct {
-	ID              int    `json:"id"`
+	ID int `json:"id"`
 	// channel ID
 	Channel         string `json:"channel,omitempty"`
 	Text            string `json:"text,omitempty"`
 	Type            string `json:"type,omitempty"`
 	ThreadTimestamp string `json:"thread_ts,omitempty"`
+	ThreadBroadcast bool   `json:"reply_broadcast,omitempty"`
 }
 
 // Message is an auxiliary type to allow us to have a message containing sub messages
@@ -26,9 +27,12 @@ type Msg struct {
 	Timestamp       string       `json:"ts,omitempty"`
 	ThreadTimestamp string       `json:"thread_ts,omitempty"`
 	IsStarred       bool         `json:"is_starred,omitempty"`
-	PinnedTo        []string     `json:"pinned_to, omitempty"`
+	PinnedTo        []string     `json:"pinned_to,omitempty"`
 	Attachments     []Attachment `json:"attachments,omitempty"`
 	Edited          *Edited      `json:"edited,omitempty"`
+	LastRead        string       `json:"last_read,omitempty"`
+	Subscribed      bool         `json:"subscribed,omitempty"`
+	UnreadCount     int          `json:"unread_count,omitempty"`
 
 	// Message Subtypes
 	SubType string `json:"subtype,omitempty"`
@@ -65,7 +69,7 @@ type Msg struct {
 	ParentUserId string  `json:"parent_user_id,omitempty"`
 
 	// file_share, file_comment, file_mention
-	File *File `json:"file,omitempty"`
+	Files []File `json:"files,omitempty"`
 
 	// file_share
 	Upload bool `json:"upload,omitempty"`
@@ -82,6 +86,11 @@ type Msg struct {
 
 	// reactions
 	Reactions []ItemReaction `json:"reactions,omitempty"`
+
+	// slash commands and interactive messages
+	ResponseType    string `json:"response_type,omitempty"`
+	ReplaceOriginal bool   `json:"replace_original"`
+	DeleteOriginal  bool   `json:"delete_original"`
 }
 
 // Icon is used for bot messages
@@ -109,27 +118,33 @@ type Event struct {
 
 // Ping contains information about a Ping Event
 type Ping struct {
-	ID   int    `json:"id"`
-	Type string `json:"type"`
+	ID        int    `json:"id"`
+	Type      string `json:"type"`
+	Timestamp int64  `json:"timestamp"`
 }
 
 // Pong contains information about a Pong Event
 type Pong struct {
-	Type    string `json:"type"`
-	ReplyTo int    `json:"reply_to"`
+	Type      string `json:"type"`
+	ReplyTo   int    `json:"reply_to"`
+	Timestamp int64  `json:"timestamp"`
 }
 
 // NewOutgoingMessage prepares an OutgoingMessage that the user can
 // use to send a message. Use this function to properly set the
 // messageID.
-func (rtm *RTM) NewOutgoingMessage(text string, channelID string) *OutgoingMessage {
+func (rtm *RTM) NewOutgoingMessage(text string, channelID string, options ...RTMsgOption) *OutgoingMessage {
 	id := rtm.idGen.Next()
-	return &OutgoingMessage{
+	msg := OutgoingMessage{
 		ID:      id,
 		Type:    "message",
 		Channel: channelID,
 		Text:    text,
 	}
+	for _, option := range options {
+		option(&msg)
+	}
+	return &msg
 }
 
 // NewTypingMessage prepares an OutgoingMessage that the user can
@@ -143,3 +158,21 @@ func (rtm *RTM) NewTypingMessage(channelID string) *OutgoingMessage {
 		Channel: channelID,
 	}
 }
+
+// RTMsgOption allows configuration of various options available for sending an RTM message
+type RTMsgOption func(*OutgoingMessage)
+
+// RTMsgOptionTS sets thead timestamp of an outgoing message in order to respond to a thread
+func RTMsgOptionTS(threadTimestamp string) RTMsgOption {
+	return func(msg *OutgoingMessage) {
+		msg.ThreadTimestamp = threadTimestamp
+	}
+}
+
+// RTMsgOptionBroadcast sets broadcast reply to channel to "true"
+func RTMsgOptionBroadcast() RTMsgOption {
+	return func(msg *OutgoingMessage) {
+		msg.ThreadBroadcast = true
+	}
+
+}
diff --git a/vendor/github.com/nlopes/slack/misc.go b/vendor/github.com/nlopes/slack/misc.go
index e890aa8f..69103384 100644
--- a/vendor/github.com/nlopes/slack/misc.go
+++ b/vendor/github.com/nlopes/slack/misc.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -18,29 +19,41 @@ import (
 	"time"
 )
 
-// HTTPRequester defines the minimal interface needed for an http.Client to be implemented.
-//
-// Use it in conjunction with the SetHTTPClient function to allow for other capabilities
-// like a tracing http.Client
-type HTTPRequester interface {
-	Do(*http.Request) (*http.Response, error)
+type SlackResponse struct {
+	Ok    bool   `json:"ok"`
+	Error string `json:"error"`
 }
 
-var customHTTPClient HTTPRequester
+func (t SlackResponse) Err() error {
+	if t.Ok {
+		return nil
+	}
+
+	// handle pure text based responses like chat.post
+	// which while they have a slack response in their data structure
+	// it doesn't actually get set during parsing.
+	if strings.TrimSpace(t.Error) == "" {
+		return nil
+	}
 
-// HTTPClient sets a custom http.Client
-// deprecated: in favor of SetHTTPClient()
-var HTTPClient = &http.Client{}
+	return errors.New(t.Error)
+}
 
-type WebResponse struct {
-	Ok    bool      `json:"ok"`
-	Error *WebError `json:"error"`
+// StatusCodeError represents an http response error.
+// type httpStatusCode interface { HTTPStatusCode() int } to handle it.
+type statusCodeError struct {
+	Code   int
+	Status string
 }
 
-type WebError string
+func (t statusCodeError) Error() string {
+	// TODO: this is a bad error string, should clean it up with a breaking changes
+	// merger.
+	return fmt.Sprintf("Slack server error: %s.", t.Status)
+}
 
-func (s WebError) Error() string {
-	return string(s)
+func (t statusCodeError) HTTPStatusCode() int {
+	return t.Code
 }
 
 type RateLimitedError struct {
@@ -77,7 +90,7 @@ func fileUploadReq(ctx context.Context, path, fieldname, filename string, values
 	return req, nil
 }
 
-func parseResponseBody(body io.ReadCloser, intf *interface{}, debug bool) error {
+func parseResponseBody(body io.ReadCloser, intf interface{}, debug bool) error {
 	response, err := ioutil.ReadAll(body)
 	if err != nil {
 		return err
@@ -88,10 +101,10 @@ func parseResponseBody(body io.ReadCloser, intf *interface{}, debug bool) error
 		logger.Printf("parseResponseBody: %s\n", string(response))
 	}
 
-	return json.Unmarshal(response, &intf)
+	return json.Unmarshal(response, intf)
 }
 
-func postLocalWithMultipartResponse(ctx context.Context, path, fpath, fieldname string, values url.Values, intf interface{}, debug bool) error {
+func postLocalWithMultipartResponse(ctx context.Context, client HTTPRequester, path, fpath, fieldname string, values url.Values, intf interface{}, debug bool) error {
 	fullpath, err := filepath.Abs(fpath)
 	if err != nil {
 		return err
@@ -101,16 +114,16 @@ func postLocalWithMultipartResponse(ctx context.Context, path, fpath, fieldname
 		return err
 	}
 	defer file.Close()
-	return postWithMultipartResponse(ctx, path, filepath.Base(fpath), fieldname, values, file, intf, debug)
+	return postWithMultipartResponse(ctx, client, path, filepath.Base(fpath), fieldname, values, file, intf, debug)
 }
 
-func postWithMultipartResponse(ctx context.Context, path, name, fieldname string, values url.Values, r io.Reader, intf interface{}, debug bool) error {
+func postWithMultipartResponse(ctx context.Context, client HTTPRequester, path, name, fieldname string, values url.Values, r io.Reader, intf interface{}, debug bool) error {
 	req, err := fileUploadReq(ctx, SLACK_API+path, fieldname, name, values, r)
 	if err != nil {
 		return err
 	}
 	req = req.WithContext(ctx)
-	resp, err := getHTTPClient().Do(req)
+	resp, err := client.Do(req)
 	if err != nil {
 		return err
 	}
@@ -127,22 +140,15 @@ func postWithMultipartResponse(ctx context.Context, path, name, fieldname string
 	// Slack seems to send an HTML body along with 5xx error codes. Don't parse it.
 	if resp.StatusCode != http.StatusOK {
 		logResponse(resp, debug)
-		return fmt.Errorf("Slack server error: %s.", resp.Status)
+		return statusCodeError{Code: resp.StatusCode, Status: resp.Status}
 	}
 
-	return parseResponseBody(resp.Body, &intf, debug)
+	return parseResponseBody(resp.Body, intf, debug)
 }
 
-func postForm(ctx context.Context, endpoint string, values url.Values, intf interface{}, debug bool) error {
-	reqBody := strings.NewReader(values.Encode())
-	req, err := http.NewRequest("POST", endpoint, reqBody)
-	if err != nil {
-		return err
-	}
-	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-
+func doPost(ctx context.Context, client HTTPRequester, req *http.Request, intf interface{}, debug bool) error {
 	req = req.WithContext(ctx)
-	resp, err := getHTTPClient().Do(req)
+	resp, err := client.Do(req)
 	if err != nil {
 		return err
 	}
@@ -159,19 +165,43 @@ func postForm(ctx context.Context, endpoint string, values url.Values, intf inte
 	// Slack seems to send an HTML body along with 5xx error codes. Don't parse it.
 	if resp.StatusCode != http.StatusOK {
 		logResponse(resp, debug)
-		return fmt.Errorf("Slack server error: %s.", resp.Status)
+		return statusCodeError{Code: resp.StatusCode, Status: resp.Status}
+	}
+
+	return parseResponseBody(resp.Body, intf, debug)
+}
+
+// post JSON.
+func postJSON(ctx context.Context, client HTTPRequester, endpoint, token string, json []byte, intf interface{}, debug bool) error {
+	reqBody := bytes.NewBuffer(json)
+	req, err := http.NewRequest("POST", endpoint, reqBody)
+	if err != nil {
+		return err
 	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+	return doPost(ctx, client, req, intf, debug)
+}
 
-	return parseResponseBody(resp.Body, &intf, debug)
+// post a url encoded form.
+func postForm(ctx context.Context, client HTTPRequester, endpoint string, values url.Values, intf interface{}, debug bool) error {
+	reqBody := strings.NewReader(values.Encode())
+	req, err := http.NewRequest("POST", endpoint, reqBody)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	return doPost(ctx, client, req, intf, debug)
 }
 
-func post(ctx context.Context, path string, values url.Values, intf interface{}, debug bool) error {
-	return postForm(ctx, SLACK_API+path, values, intf, debug)
+// post to a slack web method.
+func postSlackMethod(ctx context.Context, client HTTPRequester, path string, values url.Values, intf interface{}, debug bool) error {
+	return postForm(ctx, client, SLACK_API+path, values, intf, debug)
 }
 
-func parseAdminResponse(ctx context.Context, method string, teamName string, values url.Values, intf interface{}, debug bool) error {
+func parseAdminResponse(ctx context.Context, client HTTPRequester, method string, teamName string, values url.Values, intf interface{}, debug bool) error {
 	endpoint := fmt.Sprintf(SLACK_WEB_API_FORMAT, teamName, method, time.Now().Unix())
-	return postForm(ctx, endpoint, values, intf, debug)
+	return postForm(ctx, client, endpoint, values, intf, debug)
 }
 
 func logResponse(resp *http.Response, debug bool) error {
@@ -187,17 +217,24 @@ func logResponse(resp *http.Response, debug bool) error {
 	return nil
 }
 
-func getHTTPClient() HTTPRequester {
-	if customHTTPClient != nil {
-		return customHTTPClient
-	}
+func okJSONHandler(rw http.ResponseWriter, r *http.Request) {
+	rw.Header().Set("Content-Type", "application/json")
+	response, _ := json.Marshal(SlackResponse{
+		Ok: true,
+	})
+	rw.Write(response)
+}
+
+type errorString string
 
-	return HTTPClient
+func (t errorString) Error() string {
+	return string(t)
 }
 
-// SetHTTPClient allows you to specify a custom http.Client
-// Use this instead of the package level HTTPClient variable if you want to use a custom client like the
-// Stackdriver Trace HTTPClient https://godoc.org/cloud.google.com/go/trace#HTTPClient
-func SetHTTPClient(client HTTPRequester) {
-	customHTTPClient = client
+// timerReset safely reset a timer, see time.Timer.Reset for details.
+func timerReset(t *time.Timer, d time.Duration) {
+	if !t.Stop() {
+		<-t.C
+	}
+	t.Reset(d)
 }
diff --git a/vendor/github.com/nlopes/slack/oauth.go b/vendor/github.com/nlopes/slack/oauth.go
index db10aa1b..378af4a5 100644
--- a/vendor/github.com/nlopes/slack/oauth.go
+++ b/vendor/github.com/nlopes/slack/oauth.go
@@ -55,7 +55,7 @@ func GetOAuthResponseContext(ctx context.Context, clientID, clientSecret, code,
 		"redirect_uri":  {redirectURI},
 	}
 	response := &OAuthResponse{}
-	err = post(ctx, "oauth.access", values, response, debug)
+	err = postSlackMethod(ctx, customHTTPClient, "oauth.access", values, response, debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/pins.go b/vendor/github.com/nlopes/slack/pins.go
index a20f8f73..34863f17 100644
--- a/vendor/github.com/nlopes/slack/pins.go
+++ b/vendor/github.com/nlopes/slack/pins.go
@@ -21,25 +21,24 @@ func (api *Client) AddPin(channel string, item ItemRef) error {
 func (api *Client) AddPinContext(ctx context.Context, channel string, item ItemRef) error {
 	values := url.Values{
 		"channel": {channel},
-		"token":   {api.config.token},
+		"token":   {api.token},
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "pins.add", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "pins.add", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // RemovePin un-pins an item from a channel
@@ -51,25 +50,24 @@ func (api *Client) RemovePin(channel string, item ItemRef) error {
 func (api *Client) RemovePinContext(ctx context.Context, channel string, item ItemRef) error {
 	values := url.Values{
 		"channel": {channel},
-		"token":   {api.config.token},
+		"token":   {api.token},
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "pins.remove", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "pins.remove", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // ListPins returns information about the items a user reacted to.
@@ -81,10 +79,11 @@ func (api *Client) ListPins(channel string) ([]Item, *Paging, error) {
 func (api *Client) ListPinsContext(ctx context.Context, channel string) ([]Item, *Paging, error) {
 	values := url.Values{
 		"channel": {channel},
-		"token":   {api.config.token},
+		"token":   {api.token},
 	}
+
 	response := &listPinsResponseFull{}
-	err := post(ctx, "pins.list", values, response, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, "pins.list", values, response, api.debug)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/reactions.go b/vendor/github.com/nlopes/slack/reactions.go
index 9da59241..5eabde63 100644
--- a/vendor/github.com/nlopes/slack/reactions.go
+++ b/vendor/github.com/nlopes/slack/reactions.go
@@ -136,31 +136,30 @@ func (api *Client) AddReaction(name string, item ItemRef) error {
 // AddReactionContext adds a reaction emoji to a message, file or file comment with a custom context.
 func (api *Client) AddReactionContext(ctx context.Context, name string, item ItemRef) error {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if name != "" {
 		values.Set("name", name)
 	}
 	if item.Channel != "" {
-		values.Set("channel", string(item.Channel))
+		values.Set("channel", item.Channel)
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "reactions.add", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "reactions.add", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // RemoveReaction removes a reaction emoji from a message, file or file comment.
@@ -171,31 +170,30 @@ func (api *Client) RemoveReaction(name string, item ItemRef) error {
 // RemoveReactionContext removes a reaction emoji from a message, file or file comment with a custom context.
 func (api *Client) RemoveReactionContext(ctx context.Context, name string, item ItemRef) error {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if name != "" {
 		values.Set("name", name)
 	}
 	if item.Channel != "" {
-		values.Set("channel", string(item.Channel))
+		values.Set("channel", item.Channel)
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "reactions.remove", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "reactions.remove", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // GetReactions returns details about the reactions on an item.
@@ -206,25 +204,26 @@ func (api *Client) GetReactions(item ItemRef, params GetReactionsParameters) ([]
 // GetReactionsContext returns details about the reactions on an item with a custom context
 func (api *Client) GetReactionsContext(ctx context.Context, item ItemRef, params GetReactionsParameters) ([]ItemReaction, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if item.Channel != "" {
-		values.Set("channel", string(item.Channel))
+		values.Set("channel", item.Channel)
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
 	if params.Full != DEFAULT_REACTIONS_FULL {
 		values.Set("full", strconv.FormatBool(params.Full))
 	}
+
 	response := &getReactionsResponseFull{}
-	if err := post(ctx, "reactions.get", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "reactions.get", values, response, api.debug); err != nil {
 		return nil, err
 	}
 	if !response.Ok {
@@ -241,7 +240,7 @@ func (api *Client) ListReactions(params ListReactionsParameters) ([]ReactedItem,
 // ListReactionsContext returns information about the items a user reacted to with a custom context.
 func (api *Client) ListReactionsContext(ctx context.Context, params ListReactionsParameters) ([]ReactedItem, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.User != DEFAULT_REACTIONS_USER {
 		values.Add("user", params.User)
@@ -255,8 +254,9 @@ func (api *Client) ListReactionsContext(ctx context.Context, params ListReaction
 	if params.Full != DEFAULT_REACTIONS_FULL {
 		values.Add("full", strconv.FormatBool(params.Full))
 	}
+
 	response := &listReactionsResponseFull{}
-	err := post(ctx, "reactions.list", values, response, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, "reactions.list", values, response, api.debug)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/rtm.go b/vendor/github.com/nlopes/slack/rtm.go
index bb3cde1b..41a136eb 100644
--- a/vendor/github.com/nlopes/slack/rtm.go
+++ b/vendor/github.com/nlopes/slack/rtm.go
@@ -3,16 +3,34 @@ package slack
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 	"net/url"
+	"sync"
 	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+const (
+	websocketDefaultTimeout = 10 * time.Second
+	defaultPingInterval     = 30 * time.Second
+)
+
+const (
+	rtmEventTypeAck                 = ""
+	rtmEventTypeHello               = "hello"
+	rtmEventTypeGoodbye             = "goodbye"
+	rtmEventTypePong                = "pong"
+	rtmEventTypeDesktopNotification = "desktop_notification"
 )
 
 // StartRTM calls the "rtm.start" endpoint and returns the provided URL and the full Info block.
 //
 // To have a fully managed Websocket connection, use `NewRTM`, and call `ManageConnection()` on it.
 func (api *Client) StartRTM() (info *Info, websocketURL string, err error) {
-	return api.StartRTMContext(context.Background())
+	ctx, cancel := context.WithTimeout(context.Background(), websocketDefaultTimeout)
+	defer cancel()
+
+	return api.StartRTMContext(ctx)
 }
 
 // StartRTMContext calls the "rtm.start" endpoint and returns the provided URL and the full Info block with a custom context.
@@ -20,69 +38,101 @@ func (api *Client) StartRTM() (info *Info, websocketURL string, err error) {
 // To have a fully managed Websocket connection, use `NewRTM`, and call `ManageConnection()` on it.
 func (api *Client) StartRTMContext(ctx context.Context) (info *Info, websocketURL string, err error) {
 	response := &infoResponseFull{}
-	err = post(ctx, "rtm.start", url.Values{"token": {api.config.token}}, response, api.debug)
+	err = postSlackMethod(ctx, api.httpclient, "rtm.start", url.Values{"token": {api.token}}, response, api.debug)
 	if err != nil {
-		return nil, "", fmt.Errorf("post: %s", err)
-	}
-	if !response.Ok {
-		return nil, "", response.Error
+		return nil, "", err
 	}
+
 	api.Debugln("Using URL:", response.Info.URL)
-	return &response.Info, response.Info.URL, nil
+	return &response.Info, response.Info.URL, response.Err()
 }
 
 // ConnectRTM calls the "rtm.connect" endpoint and returns the provided URL and the compact Info block.
 //
 // To have a fully managed Websocket connection, use `NewRTM`, and call `ManageConnection()` on it.
 func (api *Client) ConnectRTM() (info *Info, websocketURL string, err error) {
-	return api.ConnectRTMContext(context.Background())
+	ctx, cancel := context.WithTimeout(context.Background(), websocketDefaultTimeout)
+	defer cancel()
+
+	return api.ConnectRTMContext(ctx)
 }
 
-// ConnectRTM calls the "rtm.connect" endpoint and returns the provided URL and the compact Info block with a custom context.
+// ConnectRTMContext calls the "rtm.connect" endpoint and returns the
+// provided URL and the compact Info block with a custom context.
 //
 // To have a fully managed Websocket connection, use `NewRTM`, and call `ManageConnection()` on it.
 func (api *Client) ConnectRTMContext(ctx context.Context) (info *Info, websocketURL string, err error) {
 	response := &infoResponseFull{}
-	err = post(ctx, "rtm.connect", url.Values{"token": {api.config.token}}, response, api.debug)
+	err = postSlackMethod(ctx, api.httpclient, "rtm.connect", url.Values{"token": {api.token}}, response, api.debug)
 	if err != nil {
-		return nil, "", fmt.Errorf("post: %s", err)
-	}
-	if !response.Ok {
-		return nil, "", response.Error
+		api.Debugf("Failed to connect to RTM: %s", err)
+		return nil, "", err
 	}
+
 	api.Debugln("Using URL:", response.Info.URL)
-	return &response.Info, response.Info.URL, nil
+	return &response.Info, response.Info.URL, response.Err()
 }
 
-// NewRTM returns a RTM, which provides a fully managed connection to
-// Slack's websocket-based Real-Time Messaging protocol.
-func (api *Client) NewRTM() *RTM {
-	return api.NewRTMWithOptions(nil)
+// RTMOption options for the managed RTM.
+type RTMOption func(*RTM)
+
+// RTMOptionUseStart as of 11th July 2017 you should prefer setting this to false, see:
+// https://api.slack.com/changelog/2017-04-start-using-rtm-connect-and-stop-using-rtm-start
+func RTMOptionUseStart(b bool) RTMOption {
+	return func(rtm *RTM) {
+		rtm.useRTMStart = b
+	}
+}
+
+// RTMOptionDialer takes a gorilla websocket Dialer and uses it as the
+// Dialer when opening the websocket for the RTM connection.
+func RTMOptionDialer(d *websocket.Dialer) RTMOption {
+	return func(rtm *RTM) {
+		rtm.dialer = d
+	}
+}
+
+// RTMOptionPingInterval determines how often to deliver a ping message to slack.
+func RTMOptionPingInterval(d time.Duration) RTMOption {
+	return func(rtm *RTM) {
+		rtm.pingInterval = d
+		rtm.resetDeadman()
+	}
 }
 
-// NewRTMWithOptions returns a RTM, which provides a fully managed connection to
+// NewRTM returns a RTM, which provides a fully managed connection to
 // Slack's websocket-based Real-Time Messaging protocol.
-// This also allows to configure various options available for RTM API.
-func (api *Client) NewRTMWithOptions(options *RTMOptions) *RTM {
+func (api *Client) NewRTM(options ...RTMOption) *RTM {
 	result := &RTM{
 		Client:           *api,
 		IncomingEvents:   make(chan RTMEvent, 50),
 		outgoingMessages: make(chan OutgoingMessage, 20),
-		pings:            make(map[int]time.Time),
+		pingInterval:     defaultPingInterval,
+		pingDeadman:      time.NewTimer(deadmanDuration(defaultPingInterval)),
 		isConnected:      false,
 		wasIntentional:   true,
 		killChannel:      make(chan bool),
-		disconnected:     make(chan struct{}),
+		disconnected:     make(chan struct{}, 1),
 		forcePing:        make(chan bool),
 		rawEvents:        make(chan json.RawMessage),
 		idGen:            NewSafeID(1),
+		mu:               &sync.Mutex{},
 	}
 
-	if options != nil {
-		result.useRTMStart = options.UseRTMStart
-	} else {
-		result.useRTMStart = true
+	for _, opt := range options {
+		opt(result)
 	}
 
 	return result
 }
+
+// NewRTMWithOptions Deprecated just use NewRTM(RTMOptionsUseStart(true))
+// returns a RTM, which provides a fully managed connection to
+// Slack's websocket-based Real-Time Messaging protocol.
+// This also allows to configure various options available for RTM API.
+func (api *Client) NewRTMWithOptions(options *RTMOptions) *RTM {
+	if options != nil {
+		return api.NewRTM(RTMOptionUseStart(options.UseRTMStart))
+	}
+	return api.NewRTM()
+}
diff --git a/vendor/github.com/nlopes/slack/search.go b/vendor/github.com/nlopes/slack/search.go
index 0e8d65e2..e858952f 100644
--- a/vendor/github.com/nlopes/slack/search.go
+++ b/vendor/github.com/nlopes/slack/search.go
@@ -11,7 +11,7 @@ const (
 	DEFAULT_SEARCH_SORT      = "score"
 	DEFAULT_SEARCH_SORT_DIR  = "desc"
 	DEFAULT_SEARCH_HIGHLIGHT = false
-	DEFAULT_SEARCH_COUNT     = 100
+	DEFAULT_SEARCH_COUNT     = 20
 	DEFAULT_SEARCH_PAGE      = 1
 )
 
@@ -37,17 +37,18 @@ type CtxMessage struct {
 }
 
 type SearchMessage struct {
-	Type      string     `json:"type"`
-	Channel   CtxChannel `json:"channel"`
-	User      string     `json:"user"`
-	Username  string     `json:"username"`
-	Timestamp string     `json:"ts"`
-	Text      string     `json:"text"`
-	Permalink string     `json:"permalink"`
-	Previous  CtxMessage `json:"previous"`
-	Previous2 CtxMessage `json:"previous_2"`
-	Next      CtxMessage `json:"next"`
-	Next2     CtxMessage `json:"next_2"`
+	Type        string       `json:"type"`
+	Channel     CtxChannel   `json:"channel"`
+	User        string       `json:"user"`
+	Username    string       `json:"username"`
+	Timestamp   string       `json:"ts"`
+	Text        string       `json:"text"`
+	Permalink   string       `json:"permalink"`
+	Attachments []Attachment `json:"attachments"`
+	Previous    CtxMessage   `json:"previous"`
+	Previous2   CtxMessage   `json:"previous_2"`
+	Next        CtxMessage   `json:"next"`
+	Next2       CtxMessage   `json:"next_2"`
 }
 
 type SearchMessages struct {
@@ -83,7 +84,7 @@ func NewSearchParameters() SearchParameters {
 
 func (api *Client) _search(ctx context.Context, path, query string, params SearchParameters, files, messages bool) (response *searchResponseFull, error error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"query": {query},
 	}
 	if params.Sort != DEFAULT_SEARCH_SORT {
@@ -101,8 +102,9 @@ func (api *Client) _search(ctx context.Context, path, query string, params Searc
 	if params.Page != DEFAULT_SEARCH_PAGE {
 		values.Add("page", strconv.Itoa(params.Page))
 	}
+
 	response = &searchResponseFull{}
-	err := post(ctx, path, values, response, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, path, values, response, api.debug)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/slack.go b/vendor/github.com/nlopes/slack/slack.go
index 754117c1..6d1e7de9 100644
--- a/vendor/github.com/nlopes/slack/slack.go
+++ b/vendor/github.com/nlopes/slack/slack.go
@@ -5,20 +5,47 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"net/http"
 	"net/url"
 	"os"
 )
 
-var logger stdLogger // A logger that can be set by consumers
-/*
-  Added as a var so that we can change this for testing purposes
-*/
+// Added as a var so that we can change this for testing purposes
 var SLACK_API string = "https://slack.com/api/"
 var SLACK_WEB_API_FORMAT string = "https://%s.slack.com/api/users.admin.%s?t=%s"
 
-type SlackResponse struct {
-	Ok    bool   `json:"ok"`
-	Error string `json:"error"`
+// HTTPClient sets a custom http.Client
+// deprecated: in favor of SetHTTPClient()
+var HTTPClient = &http.Client{}
+
+var customHTTPClient HTTPRequester = HTTPClient
+
+// HTTPRequester defines the minimal interface needed for an http.Client to be implemented.
+//
+// Use it in conjunction with the SetHTTPClient function to allow for other capabilities
+// like a tracing http.Client
+type HTTPRequester interface {
+	Do(*http.Request) (*http.Response, error)
+}
+
+// SetHTTPClient allows you to specify a custom http.Client
+// Use this instead of the package level HTTPClient variable if you want to use a custom client like the
+// Stackdriver Trace HTTPClient https://godoc.org/cloud.google.com/go/trace#HTTPClient
+func SetHTTPClient(client HTTPRequester) {
+	customHTTPClient = client
+}
+
+// ResponseMetadata holds pagination metadata
+type ResponseMetadata struct {
+	Cursor string `json:"next_cursor"`
+}
+
+func (t *ResponseMetadata) initialize() *ResponseMetadata {
+	if t != nil {
+		return t
+	}
+
+	return &ResponseMetadata{}
 }
 
 type AuthTestResponse struct {
@@ -35,41 +62,33 @@ type authTestResponseFull struct {
 }
 
 type Client struct {
-	config struct {
-		token string
-	}
-	info  Info
-	debug bool
+	token      string
+	info       Info
+	debug      bool
+	httpclient HTTPRequester
 }
 
-// stdLogger is a logger interface compatible with both stdlib and some
-// 3rd party loggers such as logrus.
-type stdLogger interface {
-	Print(...interface{})
-	Printf(string, ...interface{})
-	Println(...interface{})
-
-	Fatal(...interface{})
-	Fatalf(string, ...interface{})
-	Fatalln(...interface{})
-
-	Panic(...interface{})
-	Panicf(string, ...interface{})
-	Panicln(...interface{})
+// Option defines an option for a Client
+type Option func(*Client)
 
-	Output(int, string) error
+// OptionHTTPClient - provide a custom http client to the slack client.
+func OptionHTTPClient(c HTTPRequester) func(*Client) {
+	return func(s *Client) {
+		s.httpclient = c
+	}
 }
 
-// SetLogger let's library users supply a logger, so that api debugging
-// can be logged along with the application's debugging info.
-func SetLogger(l stdLogger) {
-	logger = l
-}
+// New builds a slack client from the provided token and options.
+func New(token string, options ...Option) *Client {
+	s := &Client{
+		token:      token,
+		httpclient: customHTTPClient,
+	}
+
+	for _, opt := range options {
+		opt(s)
+	}
 
-// New creates new Client.
-func New(token string) *Client {
-	s := &Client{}
-	s.config.token = token
 	return s
 }
 
@@ -80,14 +99,19 @@ func (api *Client) AuthTest() (response *AuthTestResponse, error error) {
 
 // AuthTestContext tests if the user is able to do authenticated requests or not with a custom context
 func (api *Client) AuthTestContext(ctx context.Context) (response *AuthTestResponse, error error) {
+	api.Debugf("Challenging auth...")
 	responseFull := &authTestResponseFull{}
-	err := post(ctx, "auth.test", url.Values{"token": {api.config.token}}, responseFull, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, "auth.test", url.Values{"token": {api.token}}, responseFull, api.debug)
 	if err != nil {
+		api.Debugf("failed to test for auth: %s", err)
 		return nil, err
 	}
 	if !responseFull.Ok {
+		api.Debugf("auth response was not Ok: %s", responseFull.Error)
 		return nil, errors.New(responseFull.Error)
 	}
+
+	api.Debugf("Auth challenge was successful with response %+v", responseFull.AuthTestResponse)
 	return &responseFull.AuthTestResponse, nil
 }
 
@@ -97,16 +121,18 @@ func (api *Client) AuthTestContext(ctx context.Context) (response *AuthTestRespo
 func (api *Client) SetDebug(debug bool) {
 	api.debug = debug
 	if debug && logger == nil {
-		logger = log.New(os.Stdout, "nlopes/slack", log.LstdFlags|log.Lshortfile)
+		SetLogger(log.New(os.Stdout, "nlopes/slack", log.LstdFlags|log.Lshortfile))
 	}
 }
 
+// Debugf print a formatted debug line.
 func (api *Client) Debugf(format string, v ...interface{}) {
 	if api.debug {
 		logger.Output(2, fmt.Sprintf(format, v...))
 	}
 }
 
+// Debugln print a debug line.
 func (api *Client) Debugln(v ...interface{}) {
 	if api.debug {
 		logger.Output(2, fmt.Sprintln(v...))
diff --git a/vendor/github.com/nlopes/slack/slash.go b/vendor/github.com/nlopes/slack/slash.go
new file mode 100644
index 00000000..f62065a2
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/slash.go
@@ -0,0 +1,53 @@
+package slack
+
+import (
+	"net/http"
+)
+
+// SlashCommand contains information about a request of the slash command
+type SlashCommand struct {
+	Token          string `json:"token"`
+	TeamID         string `json:"team_id"`
+	TeamDomain     string `json:"team_domain"`
+	EnterpriseID   string `json:"enterprise_id,omitempty"`
+	EnterpriseName string `json:"enterprise_name,omitempty"`
+	ChannelID      string `json:"channel_id"`
+	ChannelName    string `json:"channel_name"`
+	UserID         string `json:"user_id"`
+	UserName       string `json:"user_name"`
+	Command        string `json:"command"`
+	Text           string `json:"text"`
+	ResponseURL    string `json:"response_url"`
+	TriggerID      string `json:"trigger_id"`
+}
+
+// SlashCommandParse will parse the request of the slash command
+func SlashCommandParse(r *http.Request) (s SlashCommand, err error) {
+	if err = r.ParseForm(); err != nil {
+		return s, err
+	}
+	s.Token = r.PostForm.Get("token")
+	s.TeamID = r.PostForm.Get("team_id")
+	s.TeamDomain = r.PostForm.Get("team_domain")
+	s.EnterpriseID = r.PostForm.Get("enterprise_id")
+	s.EnterpriseName = r.PostForm.Get("enterprise_name")
+	s.ChannelID = r.PostForm.Get("channel_id")
+	s.ChannelName = r.PostForm.Get("channel_name")
+	s.UserID = r.PostForm.Get("user_id")
+	s.UserName = r.PostForm.Get("user_name")
+	s.Command = r.PostForm.Get("command")
+	s.Text = r.PostForm.Get("text")
+	s.ResponseURL = r.PostForm.Get("response_url")
+	s.TriggerID = r.PostForm.Get("trigger_id")
+	return s, nil
+}
+
+// ValidateToken validates verificationTokens
+func (s SlashCommand) ValidateToken(verificationTokens ...string) bool {
+	for _, token := range verificationTokens {
+		if s.Token == token {
+			return true
+		}
+	}
+	return false
+}
diff --git a/vendor/github.com/nlopes/slack/stars.go b/vendor/github.com/nlopes/slack/stars.go
index cf4a4a11..c1e2f6cb 100644
--- a/vendor/github.com/nlopes/slack/stars.go
+++ b/vendor/github.com/nlopes/slack/stars.go
@@ -45,25 +45,24 @@ func (api *Client) AddStar(channel string, item ItemRef) error {
 func (api *Client) AddStarContext(ctx context.Context, channel string, item ItemRef) error {
 	values := url.Values{
 		"channel": {channel},
-		"token":   {api.config.token},
+		"token":   {api.token},
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "stars.add", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "stars.add", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // RemoveStar removes a starred item from a channel
@@ -75,25 +74,24 @@ func (api *Client) RemoveStar(channel string, item ItemRef) error {
 func (api *Client) RemoveStarContext(ctx context.Context, channel string, item ItemRef) error {
 	values := url.Values{
 		"channel": {channel},
-		"token":   {api.config.token},
+		"token":   {api.token},
 	}
 	if item.Timestamp != "" {
-		values.Set("timestamp", string(item.Timestamp))
+		values.Set("timestamp", item.Timestamp)
 	}
 	if item.File != "" {
-		values.Set("file", string(item.File))
+		values.Set("file", item.File)
 	}
 	if item.Comment != "" {
-		values.Set("file_comment", string(item.Comment))
+		values.Set("file_comment", item.Comment)
 	}
+
 	response := &SlackResponse{}
-	if err := post(ctx, "stars.remove", values, response, api.debug); err != nil {
+	if err := postSlackMethod(ctx, api.httpclient, "stars.remove", values, response, api.debug); err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // ListStars returns information about the stars a user added
@@ -104,7 +102,7 @@ func (api *Client) ListStars(params StarsParameters) ([]Item, *Paging, error) {
 // ListStarsContext returns information about the stars a user added with a custom context
 func (api *Client) ListStarsContext(ctx context.Context, params StarsParameters) ([]Item, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.User != DEFAULT_STARS_USER {
 		values.Add("user", params.User)
@@ -115,8 +113,9 @@ func (api *Client) ListStarsContext(ctx context.Context, params StarsParameters)
 	if params.Page != DEFAULT_STARS_PAGE {
 		values.Add("page", strconv.Itoa(params.Page))
 	}
+
 	response := &listResponseFull{}
-	err := post(ctx, "stars.list", values, response, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, "stars.list", values, response, api.debug)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/vendor/github.com/nlopes/slack/team.go b/vendor/github.com/nlopes/slack/team.go
index e70ac57e..b6e341eb 100644
--- a/vendor/github.com/nlopes/slack/team.go
+++ b/vendor/github.com/nlopes/slack/team.go
@@ -67,9 +67,9 @@ func NewAccessLogParameters() AccessLogParameters {
 	}
 }
 
-func teamRequest(ctx context.Context, path string, values url.Values, debug bool) (*TeamResponse, error) {
+func teamRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*TeamResponse, error) {
 	response := &TeamResponse{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -81,9 +81,9 @@ func teamRequest(ctx context.Context, path string, values url.Values, debug bool
 	return response, nil
 }
 
-func billableInfoRequest(ctx context.Context, path string, values url.Values, debug bool) (map[string]BillingActive, error) {
+func billableInfoRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (map[string]BillingActive, error) {
 	response := &BillableInfoResponse{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -95,9 +95,9 @@ func billableInfoRequest(ctx context.Context, path string, values url.Values, de
 	return response.BillableInfo, nil
 }
 
-func accessLogsRequest(ctx context.Context, path string, values url.Values, debug bool) (*LoginResponse, error) {
+func accessLogsRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*LoginResponse, error) {
 	response := &LoginResponse{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -115,10 +115,10 @@ func (api *Client) GetTeamInfo() (*TeamInfo, error) {
 // GetTeamInfoContext gets the Team Information of the user with a custom context
 func (api *Client) GetTeamInfoContext(ctx context.Context) (*TeamInfo, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 
-	response, err := teamRequest(ctx, "team.info", values, api.debug)
+	response, err := teamRequest(ctx, api.httpclient, "team.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -133,7 +133,7 @@ func (api *Client) GetAccessLogs(params AccessLogParameters) ([]Login, *Paging,
 // GetAccessLogsContext retrieves a page of logins according to the parameters given with a custom context
 func (api *Client) GetAccessLogsContext(ctx context.Context, params AccessLogParameters) ([]Login, *Paging, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.Count != DEFAULT_LOGINS_COUNT {
 		values.Add("count", strconv.Itoa(params.Count))
@@ -141,7 +141,8 @@ func (api *Client) GetAccessLogsContext(ctx context.Context, params AccessLogPar
 	if params.Page != DEFAULT_LOGINS_PAGE {
 		values.Add("page", strconv.Itoa(params.Page))
 	}
-	response, err := accessLogsRequest(ctx, "team.accessLogs", values, api.debug)
+
+	response, err := accessLogsRequest(ctx, api.httpclient, "team.accessLogs", values, api.debug)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -154,11 +155,11 @@ func (api *Client) GetBillableInfo(user string) (map[string]BillingActive, error
 
 func (api *Client) GetBillableInfoContext(ctx context.Context, user string) (map[string]BillingActive, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"user":  {user},
 	}
 
-	return billableInfoRequest(ctx, "team.billableInfo", values, api.debug)
+	return billableInfoRequest(ctx, api.httpclient, "team.billableInfo", values, api.debug)
 }
 
 // GetBillableInfoForTeam returns the billing_active status of all users on the team.
@@ -169,8 +170,8 @@ func (api *Client) GetBillableInfoForTeam() (map[string]BillingActive, error) {
 // GetBillableInfoForTeamContext returns the billing_active status of all users on the team with a custom context
 func (api *Client) GetBillableInfoForTeamContext(ctx context.Context) (map[string]BillingActive, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 
-	return billableInfoRequest(ctx, "team.billableInfo", values, api.debug)
+	return billableInfoRequest(ctx, api.httpclient, "team.billableInfo", values, api.debug)
 }
diff --git a/vendor/github.com/nlopes/slack/usergroups.go b/vendor/github.com/nlopes/slack/usergroups.go
index de9f9864..1e2b6442 100644
--- a/vendor/github.com/nlopes/slack/usergroups.go
+++ b/vendor/github.com/nlopes/slack/usergroups.go
@@ -40,9 +40,9 @@ type userGroupResponseFull struct {
 	SlackResponse
 }
 
-func userGroupRequest(ctx context.Context, path string, values url.Values, debug bool) (*userGroupResponseFull, error) {
+func userGroupRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*userGroupResponseFull, error) {
 	response := &userGroupResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postSlackMethod(ctx, client, path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -60,7 +60,7 @@ func (api *Client) CreateUserGroup(userGroup UserGroup) (UserGroup, error) {
 // CreateUserGroupContext creates a new user group with a custom context
 func (api *Client) CreateUserGroupContext(ctx context.Context, userGroup UserGroup) (UserGroup, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"name":  {userGroup.Name},
 	}
 
@@ -76,7 +76,7 @@ func (api *Client) CreateUserGroupContext(ctx context.Context, userGroup UserGro
 		values["channels"] = []string{strings.Join(userGroup.Prefs.Channels, ",")}
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.create", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.create", values, api.debug)
 	if err != nil {
 		return UserGroup{}, err
 	}
@@ -91,11 +91,11 @@ func (api *Client) DisableUserGroup(userGroup string) (UserGroup, error) {
 // DisableUserGroupContext disables an existing user group with a custom context
 func (api *Client) DisableUserGroupContext(ctx context.Context, userGroup string) (UserGroup, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"usergroup": {userGroup},
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.disable", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.disable", values, api.debug)
 	if err != nil {
 		return UserGroup{}, err
 	}
@@ -110,11 +110,11 @@ func (api *Client) EnableUserGroup(userGroup string) (UserGroup, error) {
 // EnableUserGroupContext enables an existing user group with a custom context
 func (api *Client) EnableUserGroupContext(ctx context.Context, userGroup string) (UserGroup, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"usergroup": {userGroup},
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.enable", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.enable", values, api.debug)
 	if err != nil {
 		return UserGroup{}, err
 	}
@@ -129,10 +129,10 @@ func (api *Client) GetUserGroups() ([]UserGroup, error) {
 // GetUserGroupsContext returns a list of user groups for the team with a custom context
 func (api *Client) GetUserGroupsContext(ctx context.Context) ([]UserGroup, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.list", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.list", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -147,7 +147,7 @@ func (api *Client) UpdateUserGroup(userGroup UserGroup) (UserGroup, error) {
 // UpdateUserGroupContext will update an existing user group with a custom context
 func (api *Client) UpdateUserGroupContext(ctx context.Context, userGroup UserGroup) (UserGroup, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"usergroup": {userGroup.ID},
 	}
 
@@ -163,7 +163,7 @@ func (api *Client) UpdateUserGroupContext(ctx context.Context, userGroup UserGro
 		values["description"] = []string{userGroup.Description}
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.update", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.update", values, api.debug)
 	if err != nil {
 		return UserGroup{}, err
 	}
@@ -178,11 +178,11 @@ func (api *Client) GetUserGroupMembers(userGroup string) ([]string, error) {
 // GetUserGroupMembersContext will retrieve the current list of users in a group with a custom context
 func (api *Client) GetUserGroupMembersContext(ctx context.Context, userGroup string) ([]string, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"usergroup": {userGroup},
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.users.list", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.users.list", values, api.debug)
 	if err != nil {
 		return []string{}, err
 	}
@@ -197,12 +197,12 @@ func (api *Client) UpdateUserGroupMembers(userGroup string, members string) (Use
 // UpdateUserGroupMembersContext will update the members of an existing user group with a custom context
 func (api *Client) UpdateUserGroupMembersContext(ctx context.Context, userGroup string, members string) (UserGroup, error) {
 	values := url.Values{
-		"token":     {api.config.token},
+		"token":     {api.token},
 		"usergroup": {userGroup},
 		"users":     {members},
 	}
 
-	response, err := userGroupRequest(ctx, "usergroups.users.update", values, api.debug)
+	response, err := userGroupRequest(ctx, api.httpclient, "usergroups.users.update", values, api.debug)
 	if err != nil {
 		return UserGroup{}, err
 	}
diff --git a/vendor/github.com/nlopes/slack/users.go b/vendor/github.com/nlopes/slack/users.go
index f7fbd0d2..0dd20db5 100644
--- a/vendor/github.com/nlopes/slack/users.go
+++ b/vendor/github.com/nlopes/slack/users.go
@@ -5,41 +5,103 @@ import (
 	"encoding/json"
 	"errors"
 	"net/url"
+	"strconv"
 )
 
 const (
 	DEFAULT_USER_PHOTO_CROP_X = -1
 	DEFAULT_USER_PHOTO_CROP_Y = -1
 	DEFAULT_USER_PHOTO_CROP_W = -1
+	errPaginationComplete     = errorString("pagination complete")
 )
 
 // UserProfile contains all the information details of a given user
 type UserProfile struct {
-  FirstName             string `json:"first_name"`
-  LastName              string `json:"last_name"`
-  RealName              string `json:"real_name"`
-  RealNameNormalized    string `json:"real_name_normalized"`
-  DisplayName           string `json:"display_name"`
-  DisplayNameNormalized string `json:"display_name_normalized"`
-  Email                 string `json:"email"`
-  Skype                 string `json:"skype"`
-  Phone                 string `json:"phone"`
-  Image24               string `json:"image_24"`
-  Image32               string `json:"image_32"`
-  Image48               string `json:"image_48"`
-  Image72               string `json:"image_72"`
-  Image192              string `json:"image_192"`
-  ImageOriginal         string `json:"image_original"`
-  Title                 string `json:"title"`
-  BotID                 string `json:"bot_id,omitempty"`
-  ApiAppID              string `json:"api_app_id,omitempty"`
-  StatusText            string `json:"status_text,omitempty"`
-  StatusEmoji           string `json:"status_emoji,omitempty"`
+	FirstName             string                  `json:"first_name"`
+	LastName              string                  `json:"last_name"`
+	RealName              string                  `json:"real_name"`
+	RealNameNormalized    string                  `json:"real_name_normalized"`
+	DisplayName           string                  `json:"display_name"`
+	DisplayNameNormalized string                  `json:"display_name_normalized"`
+	Email                 string                  `json:"email"`
+	Skype                 string                  `json:"skype"`
+	Phone                 string                  `json:"phone"`
+	Image24               string                  `json:"image_24"`
+	Image32               string                  `json:"image_32"`
+	Image48               string                  `json:"image_48"`
+	Image72               string                  `json:"image_72"`
+	Image192              string                  `json:"image_192"`
+	ImageOriginal         string                  `json:"image_original"`
+	Title                 string                  `json:"title"`
+	BotID                 string                  `json:"bot_id,omitempty"`
+	ApiAppID              string                  `json:"api_app_id,omitempty"`
+	StatusText            string                  `json:"status_text,omitempty"`
+	StatusEmoji           string                  `json:"status_emoji,omitempty"`
+	Team                  string                  `json:"team"`
+	Fields                UserProfileCustomFields `json:"fields"`
+}
+
+// UserProfileCustomFields represents user profile's custom fields.
+// Slack API's response data type is inconsistent so we use the struct.
+// For detail, please see below.
+// https://github.com/nlopes/slack/pull/298#discussion_r185159233
+type UserProfileCustomFields struct {
+	fields map[string]UserProfileCustomField
+}
+
+// UnmarshalJSON is the implementation of the json.Unmarshaler interface.
+func (fields *UserProfileCustomFields) UnmarshalJSON(b []byte) error {
+	// https://github.com/nlopes/slack/pull/298#discussion_r185159233
+	if string(b) == "[]" {
+		return nil
+	}
+	return json.Unmarshal(b, &fields.fields)
+}
+
+// MarshalJSON is the implementation of the json.Marshaler interface.
+func (fields UserProfileCustomFields) MarshalJSON() ([]byte, error) {
+	if len(fields.fields) == 0 {
+		return []byte("[]"), nil
+	}
+	return json.Marshal(fields.fields)
+}
+
+// ToMap returns a map of custom fields.
+func (fields *UserProfileCustomFields) ToMap() map[string]UserProfileCustomField {
+	return fields.fields
+}
+
+// Len returns the number of custom fields.
+func (fields *UserProfileCustomFields) Len() int {
+	return len(fields.fields)
+}
+
+// SetMap sets a map of custom fields.
+func (fields *UserProfileCustomFields) SetMap(m map[string]UserProfileCustomField) {
+	fields.fields = m
+}
+
+// FieldsMap returns a map of custom fields.
+func (profile *UserProfile) FieldsMap() map[string]UserProfileCustomField {
+	return profile.Fields.ToMap()
+}
+
+// SetFieldsMap sets a map of custom fields.
+func (profile *UserProfile) SetFieldsMap(m map[string]UserProfileCustomField) {
+	profile.Fields.SetMap(m)
+}
+
+// UserProfileCustomField represents a custom user profile field
+type UserProfileCustomField struct {
+	Value string `json:"value"`
+	Alt   string `json:"alt"`
+	Label string `json:"label"`
 }
 
 // User contains all the information of a user
 type User struct {
 	ID                string      `json:"id"`
+	TeamID            string      `json:"team_id"`
 	Name              string      `json:"name"`
 	Deleted           bool        `json:"deleted"`
 	Color             string      `json:"color"`
@@ -54,9 +116,12 @@ type User struct {
 	IsPrimaryOwner    bool        `json:"is_primary_owner"`
 	IsRestricted      bool        `json:"is_restricted"`
 	IsUltraRestricted bool        `json:"is_ultra_restricted"`
+	IsStranger        bool        `json:"is_stranger"`
+	IsAppUser         bool        `json:"is_app_user"`
 	Has2FA            bool        `json:"has_2fa"`
 	HasFiles          bool        `json:"has_files"`
 	Presence          string      `json:"presence"`
+	Locale            string      `json:"locale"`
 }
 
 // UserPresence contains details about a user online status
@@ -103,10 +168,11 @@ type TeamIdentity struct {
 }
 
 type userResponseFull struct {
-	Members      []User                  `json:"members,omitempty"` // ListUsers
-	User         `json:"user,omitempty"` // GetUserInfo
-	UserPresence                         // GetUserPresence
+	Members []User `json:"members,omitempty"`
+	User    `json:"user,omitempty"`
+	UserPresence
 	SlackResponse
+	Metadata ResponseMetadata `json:"response_metadata"`
 }
 
 type UserSetPhotoParams struct {
@@ -123,9 +189,9 @@ func NewUserSetPhotoParams() UserSetPhotoParams {
 	}
 }
 
-func userRequest(ctx context.Context, path string, values url.Values, debug bool) (*userResponseFull, error) {
+func userRequest(ctx context.Context, client HTTPRequester, path string, values url.Values, debug bool) (*userResponseFull, error) {
 	response := &userResponseFull{}
-	err := post(ctx, path, values, response, debug)
+	err := postForm(ctx, client, SLACK_API+path, values, response, debug)
 	if err != nil {
 		return nil, err
 	}
@@ -143,10 +209,11 @@ func (api *Client) GetUserPresence(user string) (*UserPresence, error) {
 // GetUserPresenceContext will retrieve the current presence status of given user with a custom context.
 func (api *Client) GetUserPresenceContext(ctx context.Context, user string) (*UserPresence, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"user":  {user},
 	}
-	response, err := userRequest(ctx, "users.getPresence", values, api.debug)
+
+	response, err := userRequest(ctx, api.httpclient, "users.getPresence", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -161,32 +228,138 @@ func (api *Client) GetUserInfo(user string) (*User, error) {
 // GetUserInfoContext will retrieve the complete user information with a custom context
 func (api *Client) GetUserInfoContext(ctx context.Context, user string) (*User, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 		"user":  {user},
 	}
-	response, err := userRequest(ctx, "users.info", values, api.debug)
+
+	response, err := userRequest(ctx, api.httpclient, "users.info", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
 	return &response.User, nil
 }
 
+// GetUsersOption options for the GetUsers method call.
+type GetUsersOption func(*UserPagination)
+
+// GetUsersOptionLimit limit the number of users returned
+func GetUsersOptionLimit(n int) GetUsersOption {
+	return func(p *UserPagination) {
+		p.limit = n
+	}
+}
+
+// GetUsersOptionPresence include user presence
+func GetUsersOptionPresence(n bool) GetUsersOption {
+	return func(p *UserPagination) {
+		p.presence = n
+	}
+}
+
+func newUserPagination(c *Client, options ...GetUsersOption) (up UserPagination) {
+	up = UserPagination{
+		c:     c,
+		limit: 200, // per slack api documentation.
+	}
+
+	for _, opt := range options {
+		opt(&up)
+	}
+
+	return up
+}
+
+// UserPagination allows for paginating over the users
+type UserPagination struct {
+	Users        []User
+	limit        int
+	presence     bool
+	previousResp *ResponseMetadata
+	c            *Client
+}
+
+// Done checks if the pagination has completed
+func (UserPagination) Done(err error) bool {
+	return err == errPaginationComplete
+}
+
+// Failure checks if pagination failed.
+func (t UserPagination) Failure(err error) error {
+	if t.Done(err) {
+		return nil
+	}
+
+	return err
+}
+
+func (t UserPagination) Next(ctx context.Context) (_ UserPagination, err error) {
+	var (
+		resp *userResponseFull
+	)
+
+	if t.c == nil || (t.previousResp != nil && t.previousResp.Cursor == "") {
+		return t, errPaginationComplete
+	}
+
+	t.previousResp = t.previousResp.initialize()
+
+	values := url.Values{
+		"limit":    {strconv.Itoa(t.limit)},
+		"presence": {strconv.FormatBool(t.presence)},
+		"token":    {t.c.token},
+		"cursor":   {t.previousResp.Cursor},
+	}
+
+	if resp, err = userRequest(ctx, t.c.httpclient, "users.list", values, t.c.debug); err != nil {
+		return t, err
+	}
+
+	t.c.Debugf("GetUsersContext: got %d users; metadata %v", len(resp.Members), resp.Metadata)
+	t.Users = resp.Members
+	t.previousResp = &resp.Metadata
+
+	return t, nil
+}
+
+// GetUsersPaginated fetches users in a paginated fashion, see GetUsersContext for usage.
+func (api *Client) GetUsersPaginated(options ...GetUsersOption) UserPagination {
+	return newUserPagination(api, options...)
+}
+
 // GetUsers returns the list of users (with their detailed information)
 func (api *Client) GetUsers() ([]User, error) {
 	return api.GetUsersContext(context.Background())
 }
 
 // GetUsersContext returns the list of users (with their detailed information) with a custom context
-func (api *Client) GetUsersContext(ctx context.Context) ([]User, error) {
+func (api *Client) GetUsersContext(ctx context.Context) (results []User, err error) {
+	var (
+		p UserPagination
+	)
+
+	for p = api.GetUsersPaginated(); !p.Done(err); p, err = p.Next(ctx) {
+		results = append(results, p.Users...)
+	}
+
+	return results, p.Failure(err)
+}
+
+// GetUserByEmail will retrieve the complete user information by email
+func (api *Client) GetUserByEmail(email string) (*User, error) {
+	return api.GetUserByEmailContext(context.Background(), email)
+}
+
+// GetUserByEmailContext will retrieve the complete user information by email with a custom context
+func (api *Client) GetUserByEmailContext(ctx context.Context, email string) (*User, error) {
 	values := url.Values{
-		"token":    {api.config.token},
-		"presence": {"1"},
+		"token": {api.token},
+		"email": {email},
 	}
-	response, err := userRequest(ctx, "users.list", values, api.debug)
+	response, err := userRequest(ctx, api.httpclient, "users.lookupByEmail", values, api.debug)
 	if err != nil {
 		return nil, err
 	}
-	return response.Members, nil
+	return &response.User, nil
 }
 
 // SetUserAsActive marks the currently authenticated user as active
@@ -195,11 +368,12 @@ func (api *Client) SetUserAsActive() error {
 }
 
 // SetUserAsActiveContext marks the currently authenticated user as active with a custom context
-func (api *Client) SetUserAsActiveContext(ctx context.Context) error {
+func (api *Client) SetUserAsActiveContext(ctx context.Context) (err error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
-	_, err := userRequest(ctx, "users.setActive", values, api.debug)
+
+	_, err = userRequest(ctx, api.httpclient, "users.setActive", values, api.debug)
 	return err
 }
 
@@ -211,15 +385,12 @@ func (api *Client) SetUserPresence(presence string) error {
 // SetUserPresenceContext changes the currently authenticated user presence with a custom context
 func (api *Client) SetUserPresenceContext(ctx context.Context, presence string) error {
 	values := url.Values{
-		"token":    {api.config.token},
+		"token":    {api.token},
 		"presence": {presence},
 	}
-	_, err := userRequest(ctx, "users.setPresence", values, api.debug)
-	if err != nil {
-		return err
-	}
-	return nil
 
+	_, err := userRequest(ctx, api.httpclient, "users.setPresence", values, api.debug)
+	return err
 }
 
 // GetUserIdentity will retrieve user info available per identity scopes
@@ -230,10 +401,11 @@ func (api *Client) GetUserIdentity() (*UserIdentityResponse, error) {
 // GetUserIdentityContext will retrieve user info available per identity scopes with a custom context
 func (api *Client) GetUserIdentityContext(ctx context.Context) (*UserIdentityResponse, error) {
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	response := &UserIdentityResponse{}
-	err := post(ctx, "users.identity", values, response, api.debug)
+
+	err := postForm(ctx, api.httpclient, SLACK_API+"users.identity", values, response, api.debug)
 	if err != nil {
 		return nil, err
 	}
@@ -252,25 +424,24 @@ func (api *Client) SetUserPhoto(image string, params UserSetPhotoParams) error {
 func (api *Client) SetUserPhotoContext(ctx context.Context, image string, params UserSetPhotoParams) error {
 	response := &SlackResponse{}
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
 	if params.CropX != DEFAULT_USER_PHOTO_CROP_X {
-		values.Add("crop_x", string(params.CropX))
+		values.Add("crop_x", strconv.Itoa(params.CropX))
 	}
 	if params.CropY != DEFAULT_USER_PHOTO_CROP_Y {
-		values.Add("crop_y", string(params.CropY))
+		values.Add("crop_y", strconv.Itoa(params.CropX))
 	}
 	if params.CropW != DEFAULT_USER_PHOTO_CROP_W {
-		values.Add("crop_w", string(params.CropW))
+		values.Add("crop_w", strconv.Itoa(params.CropW))
 	}
-	err := postLocalWithMultipartResponse(ctx, "users.setPhoto", image, "image", values, response, api.debug)
+
+	err := postLocalWithMultipartResponse(ctx, api.httpclient, "users.setPhoto", image, "image", values, response, api.debug)
 	if err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // DeleteUserPhoto deletes the current authenticated user's profile image
@@ -282,16 +453,15 @@ func (api *Client) DeleteUserPhoto() error {
 func (api *Client) DeleteUserPhotoContext(ctx context.Context) error {
 	response := &SlackResponse{}
 	values := url.Values{
-		"token": {api.config.token},
+		"token": {api.token},
 	}
-	err := post(ctx, "users.deletePhoto", values, response, api.debug)
+
+	err := postForm(ctx, api.httpclient, SLACK_API+"users.deletePhoto", values, response, api.debug)
 	if err != nil {
 		return err
 	}
-	if !response.Ok {
-		return errors.New(response.Error)
-	}
-	return nil
+
+	return response.Err()
 }
 
 // SetUserCustomStatus will set a custom status and emoji for the currently
@@ -331,13 +501,12 @@ func (api *Client) SetUserCustomStatusContext(ctx context.Context, statusText, s
 	}
 
 	values := url.Values{
-		"token":   {api.config.token},
+		"token":   {api.token},
 		"profile": {string(profile)},
 	}
 
 	response := &userResponseFull{}
-
-	if err = post(ctx, "users.profile.set", values, response, api.debug); err != nil {
+	if err = postForm(ctx, api.httpclient, SLACK_API+"users.profile.set", values, response, api.debug); err != nil {
 		return err
 	}
 
@@ -359,3 +528,31 @@ func (api *Client) UnsetUserCustomStatus() error {
 func (api *Client) UnsetUserCustomStatusContext(ctx context.Context) error {
 	return api.SetUserCustomStatusContext(ctx, "", "")
 }
+
+// GetUserProfile retrieves a user's profile information.
+func (api *Client) GetUserProfile(userID string, includeLabels bool) (*UserProfile, error) {
+	return api.GetUserProfileContext(context.Background(), userID, includeLabels)
+}
+
+type getUserProfileResponse struct {
+	SlackResponse
+	Profile *UserProfile `json:"profile"`
+}
+
+// GetUserProfileContext retrieves a user's profile information with a context.
+func (api *Client) GetUserProfileContext(ctx context.Context, userID string, includeLabels bool) (*UserProfile, error) {
+	values := url.Values{"token": {api.token}, "user": {userID}}
+	if includeLabels {
+		values.Add("include_labels", "true")
+	}
+	resp := &getUserProfileResponse{}
+
+	err := postSlackMethod(ctx, api.httpclient, "users.profile.get", values, &resp, api.debug)
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Ok {
+		return nil, errors.New(resp.Error)
+	}
+	return resp.Profile, nil
+}
diff --git a/vendor/github.com/nlopes/slack/webhooks.go b/vendor/github.com/nlopes/slack/webhooks.go
new file mode 100644
index 00000000..870a8d8b
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/webhooks.go
@@ -0,0 +1,33 @@
+package slack
+
+import (
+	"github.com/pkg/errors"
+	"net/http"
+	"bytes"
+	"encoding/json"
+)
+
+type WebhookMessage struct {
+	Text    		string 				`json:"text,omitempty"`
+	Attachments []Attachment	`json:"attachments,omitempty"`
+}
+
+func PostWebhook(url string, msg *WebhookMessage) error {
+	raw, err := json.Marshal(msg)
+
+	if err != nil {
+		return errors.Wrap(err, "marshal failed")
+	}
+
+	response, err := http.Post(url, "application/json", bytes.NewReader(raw));
+
+	if err != nil {
+		return errors.Wrap(err, "failed to post webhook")
+	}
+
+	if response.StatusCode != http.StatusOK {
+		return statusCodeError{Code: response.StatusCode, Status: response.Status}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/nlopes/slack/websocket.go b/vendor/github.com/nlopes/slack/websocket.go
index 77906e07..242acf40 100644
--- a/vendor/github.com/nlopes/slack/websocket.go
+++ b/vendor/github.com/nlopes/slack/websocket.go
@@ -3,9 +3,10 @@ package slack
 import (
 	"encoding/json"
 	"errors"
+	"sync"
 	"time"
 
-	"golang.org/x/net/websocket"
+	"github.com/gorilla/websocket"
 )
 
 const (
@@ -19,8 +20,9 @@ const (
 //
 // Create this element with Client's NewRTM() or NewRTMWithOptions(*RTMOptions)
 type RTM struct {
-	idGen IDGenerator
-	pings map[int]time.Time
+	idGen        IDGenerator
+	pingInterval time.Duration
+	pingDeadman  *time.Timer
 
 	// Connection life-cycle
 	conn             *websocket.Conn
@@ -44,6 +46,13 @@ type RTM struct {
 	// rtm.start to connect to Slack, otherwise it will use
 	// rtm.connect
 	useRTMStart bool
+
+	// dialer is a gorilla/websocket Dialer. If nil, use the default
+	// Dialer.
+	dialer *websocket.Dialer
+
+	// mu is mutex used to prevent RTM connection race conditions
+	mu *sync.Mutex
 }
 
 // RTMOptions allows configuration of various options available for RTM messaging
@@ -60,9 +69,17 @@ type RTMOptions struct {
 
 // Disconnect and wait, blocking until a successful disconnection.
 func (rtm *RTM) Disconnect() error {
-	// this channel is always closed on disconnect. lets the ManagedConnection() function
-	// properly clean up.
-	close(rtm.disconnected)
+	// avoid RTM disconnect race conditions
+	rtm.mu.Lock()
+	defer rtm.mu.Unlock()
+
+	// always push into the disconnected channel when invoked,
+	// this lets the ManagedConnection() function properly clean up.
+	// if the buffer is full then just continue on.
+	select {
+	case rtm.disconnected <- struct{}{}:
+	default:
+	}
 
 	if !rtm.isConnected {
 		return errors.New("Invalid call to Disconnect - Slack API is already disconnected")
@@ -72,12 +89,6 @@ func (rtm *RTM) Disconnect() error {
 	return nil
 }
 
-// Reconnect only makes sense if you've successfully disconnectd with Disconnect().
-func (rtm *RTM) Reconnect() error {
-	logger.Println("RTM::Reconnect not implemented!")
-	return nil
-}
-
 // GetInfo returns the info structure received when calling
 // "startrtm", holding all channels, groups and other metadata needed
 // to implement a full chat client. It will be non-nil after a call to
@@ -97,3 +108,11 @@ func (rtm *RTM) SendMessage(msg *OutgoingMessage) {
 
 	rtm.outgoingMessages <- *msg
 }
+
+func (rtm *RTM) resetDeadman() {
+	timerReset(rtm.pingDeadman, deadmanDuration(rtm.pingInterval))
+}
+
+func deadmanDuration(d time.Duration) time.Duration {
+	return d * 4
+}
diff --git a/vendor/github.com/nlopes/slack/websocket_internals.go b/vendor/github.com/nlopes/slack/websocket_internals.go
index 2a8abe6e..e8374b0d 100644
--- a/vendor/github.com/nlopes/slack/websocket_internals.go
+++ b/vendor/github.com/nlopes/slack/websocket_internals.go
@@ -63,6 +63,13 @@ func (m *MessageTooLongEvent) Error() string {
 	return fmt.Sprintf("Message too long (max %d characters)", m.MaxLength)
 }
 
+// RateLimitEvent is used when Slack warns that rate-limits are being hit.
+type RateLimitEvent struct{}
+
+func (e *RateLimitEvent) Error() string {
+	return "Messages are being sent too fast."
+}
+
 // OutgoingErrorEvent contains information in case there were errors sending messages
 type OutgoingErrorEvent struct {
 	Message  OutgoingMessage
diff --git a/vendor/github.com/nlopes/slack/websocket_managed_conn.go b/vendor/github.com/nlopes/slack/websocket_managed_conn.go
index fec07fd7..b6d1bfc8 100644
--- a/vendor/github.com/nlopes/slack/websocket_managed_conn.go
+++ b/vendor/github.com/nlopes/slack/websocket_managed_conn.go
@@ -4,10 +4,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net/http"
 	"reflect"
 	"time"
 
-	"golang.org/x/net/websocket"
+	"github.com/gorilla/websocket"
 )
 
 // ManageConnection can be called on a Slack RTM instance returned by the
@@ -24,25 +25,35 @@ import (
 //
 // The defined error events are located in websocket_internals.go.
 func (rtm *RTM) ManageConnection() {
-	var connectionCount int
-	for {
-		connectionCount++
+	var (
+		err  error
+		info *Info
+		conn *websocket.Conn
+	)
+
+	for connectionCount := 0; ; connectionCount++ {
 		// start trying to connect
 		// the returned err is already passed onto the IncomingEvents channel
-		info, conn, err := rtm.connect(connectionCount, rtm.useRTMStart)
-		// if err != nil then the connection is sucessful - otherwise it is
-		// fatal
-		if err != nil {
+		if info, conn, err = rtm.connect(connectionCount, rtm.useRTMStart); err != nil {
+			// when the connection is unsuccessful its fatal, and we need to bail out.
+			rtm.Debugf("Failed to connect with RTM on try %d: %s", connectionCount, err)
 			return
 		}
+
+		// lock to prevent data races with Disconnect particularly around isConnected
+		// and conn.
+		rtm.mu.Lock()
+		rtm.conn = conn
+		rtm.isConnected = true
 		rtm.info = info
+		rtm.mu.Unlock()
+
 		rtm.IncomingEvents <- RTMEvent{"connected", &ConnectedEvent{
 			ConnectionCount: connectionCount,
 			Info:            info,
 		}}
 
-		rtm.conn = conn
-		rtm.isConnected = true
+		rtm.Debugf("RTM connection succeeded on try %d", connectionCount)
 
 		keepRunning := make(chan bool)
 		// we're now connected (or have failed fatally) so we can set up
@@ -50,7 +61,7 @@ func (rtm *RTM) ManageConnection() {
 		go rtm.handleIncomingEvents(keepRunning)
 
 		// this should be a blocking call until the connection has ended
-		rtm.handleEvents(keepRunning, 30*time.Second)
+		rtm.handleEvents(keepRunning)
 
 		// after being disconnected we need to check if it was intentional
 		// if not then we should try to reconnect
@@ -67,6 +78,12 @@ func (rtm *RTM) ManageConnection() {
 // If useRTMStart is false then it uses rtm.connect to create the connection,
 // otherwise it uses rtm.start.
 func (rtm *RTM) connect(connectionCount int, useRTMStart bool) (*Info, *websocket.Conn, error) {
+	const (
+		errInvalidAuth      = "invalid_auth"
+		errInactiveAccount  = "account_inactive"
+		errMissingAuthToken = "not_authed"
+	)
+
 	// used to provide exponential backoff wait time with jitter before trying
 	// to connect to slack again
 	boff := &backoff{
@@ -87,10 +104,14 @@ func (rtm *RTM) connect(connectionCount int, useRTMStart bool) (*Info, *websocke
 		if err == nil {
 			return info, conn, nil
 		}
-		// check for fatal errors - currently only invalid_auth
-		if sErr, ok := err.(*WebError); ok && (sErr.Error() == "invalid_auth" || sErr.Error() == "account_inactive") {
+
+		// check for fatal errors
+		switch err.Error() {
+		case errInvalidAuth, errInactiveAccount, errMissingAuthToken:
+			rtm.Debugf("Invalid auth when connecting with RTM: %s", err)
 			rtm.IncomingEvents <- RTMEvent{"invalid_auth", &InvalidAuthEvent{}}
-			return nil, nil, sErr
+			return nil, nil, err
+		default:
 		}
 
 		// any other errors are treated as recoverable and we try again after
@@ -102,7 +123,7 @@ func (rtm *RTM) connect(connectionCount int, useRTMStart bool) (*Info, *websocke
 
 		// check if Disconnect() has been invoked.
 		select {
-		case _ = <-rtm.disconnected:
+		case <-rtm.disconnected:
 			rtm.IncomingEvents <- RTMEvent{"disconnected", &DisconnectedEvent{Intentional: true}}
 			return nil, nil, fmt.Errorf("disconnect received while trying to connect")
 		default:
@@ -119,23 +140,34 @@ func (rtm *RTM) connect(connectionCount int, useRTMStart bool) (*Info, *websocke
 // startRTMAndDial attempts to connect to the slack websocket. If useRTMStart is true,
 // then it returns the  full information returned by the "rtm.start" method on the
 // slack API. Else it uses the "rtm.connect" method to connect
-func (rtm *RTM) startRTMAndDial(useRTMStart bool) (*Info, *websocket.Conn, error) {
-	var info *Info
-	var url string
-	var err error
+func (rtm *RTM) startRTMAndDial(useRTMStart bool) (info *Info, _ *websocket.Conn, err error) {
+	var (
+		url string
+	)
 
 	if useRTMStart {
+		rtm.Debugf("Starting RTM")
 		info, url, err = rtm.StartRTM()
 	} else {
+		rtm.Debugf("Connecting to RTM")
 		info, url, err = rtm.ConnectRTM()
 	}
 	if err != nil {
+		rtm.Debugf("Failed to start or connect to RTM: %s", err)
 		return nil, nil, err
 	}
 
+	rtm.Debugf("Dialing to websocket on url %s", url)
 	// Only use HTTPS for connections to prevent MITM attacks on the connection.
-	conn, err := websocketProxyDial(url, "https://api.slack.com")
+	upgradeHeader := http.Header{}
+	upgradeHeader.Add("Origin", "https://api.slack.com")
+	dialer := websocket.DefaultDialer
+	if rtm.dialer != nil {
+		dialer = rtm.dialer
+	}
+	conn, _, err := dialer.Dial(url, upgradeHeader)
 	if err != nil {
+		rtm.Debugf("Failed to dial to the websocket: %s", err)
 		return nil, nil, err
 	}
 	return info, conn, err
@@ -163,8 +195,8 @@ func (rtm *RTM) killConnection(keepRunning chan bool, intentional bool) error {
 // interval. This also sends outgoing messages that are received from the RTM's
 // outgoingMessages channel. This also handles incoming raw events from the RTM
 // rawEvents channel.
-func (rtm *RTM) handleEvents(keepRunning chan bool, interval time.Duration) {
-	ticker := time.NewTicker(interval)
+func (rtm *RTM) handleEvents(keepRunning chan bool) {
+	ticker := time.NewTicker(rtm.pingInterval)
 	defer ticker.Stop()
 	for {
 		select {
@@ -172,7 +204,12 @@ func (rtm *RTM) handleEvents(keepRunning chan bool, interval time.Duration) {
 		case intentional := <-rtm.killChannel:
 			_ = rtm.killConnection(keepRunning, intentional)
 			return
-			// send pings on ticker interval
+
+		// detect when the connection is dead.
+		case <-rtm.pingDeadman.C:
+			rtm.Debugln("deadman switch trigger disconnecting")
+			_ = rtm.killConnection(keepRunning, false)
+		// send pings on ticker interval
 		case <-ticker.C:
 			err := rtm.ping()
 			if err != nil {
@@ -190,7 +227,11 @@ func (rtm *RTM) handleEvents(keepRunning chan bool, interval time.Duration) {
 			rtm.sendOutgoingMessage(msg)
 		// listen for incoming messages that need to be parsed
 		case rawEvent := <-rtm.rawEvents:
-			rtm.handleRawEvent(rawEvent)
+			switch rtm.handleRawEvent(rawEvent) {
+			case rtmEventTypeGoodbye:
+				_ = rtm.killConnection(keepRunning, false)
+			default:
+			}
 		}
 	}
 }
@@ -208,7 +249,9 @@ func (rtm *RTM) handleIncomingEvents(keepRunning <-chan bool) {
 		case <-keepRunning:
 			return
 		default:
-			rtm.receiveIncomingEvent()
+			if err := rtm.receiveIncomingEvent(); err != nil {
+				return
+			}
 		}
 	}
 }
@@ -218,7 +261,7 @@ func (rtm *RTM) sendWithDeadline(msg interface{}) error {
 	if err := rtm.conn.SetWriteDeadline(time.Now().Add(10 * time.Second)); err != nil {
 		return err
 	}
-	if err := websocket.JSON.Send(rtm.conn, msg); err != nil {
+	if err := rtm.conn.WriteJSON(msg); err != nil {
 		return err
 	}
 	// remove write deadline
@@ -258,9 +301,7 @@ func (rtm *RTM) sendOutgoingMessage(msg OutgoingMessage) {
 func (rtm *RTM) ping() error {
 	id := rtm.idGen.Next()
 	rtm.Debugln("Sending PING ", id)
-	rtm.pings[id] = time.Now()
-
-	msg := &Ping{ID: id, Type: "ping"}
+	msg := &Ping{ID: id, Type: "ping", Timestamp: time.Now().Unix()}
 
 	if err := rtm.sendWithDeadline(msg); err != nil {
 		rtm.Debugf("RTM Error sending 'PING %d': %s", id, err.Error())
@@ -271,52 +312,62 @@ func (rtm *RTM) ping() error {
 
 // receiveIncomingEvent attempts to receive an event from the RTM's websocket.
 // This will block until a frame is available from the websocket.
-func (rtm *RTM) receiveIncomingEvent() {
+// If the read from the websocket results in a fatal error, this function will return non-nil.
+func (rtm *RTM) receiveIncomingEvent() error {
 	event := json.RawMessage{}
-	err := websocket.JSON.Receive(rtm.conn, &event)
-	if err == io.EOF {
+	err := rtm.conn.ReadJSON(&event)
+	switch {
+	case err == io.ErrUnexpectedEOF:
 		// EOF's don't seem to signify a failed connection so instead we ignore
 		// them here and detect a failed connection upon attempting to send a
 		// 'PING' message
 
-		// trigger a 'PING' to detect pontential websocket disconnect
+		// trigger a 'PING' to detect potential websocket disconnect
 		rtm.forcePing <- true
-		return
-	} else if err != nil {
+	case err != nil:
+		// All other errors from ReadJSON come from NextReader, and should
+		// kill the read loop and force a reconnect.
 		rtm.IncomingEvents <- RTMEvent{"incoming_error", &IncomingEventError{
 			ErrorObj: err,
 		}}
-		// force a ping here too?
-		return
-	} else if len(event) == 0 {
+		rtm.killChannel <- false
+		return err
+	case len(event) == 0:
 		rtm.Debugln("Received empty event")
-		return
+	default:
+		rtm.Debugln("Incoming Event:", string(event[:]))
+		rtm.rawEvents <- event
 	}
-	rtm.Debugln("Incoming Event:", string(event[:]))
-	rtm.rawEvents <- event
+	return nil
 }
 
 // handleRawEvent takes a raw JSON message received from the slack websocket
 // and handles the encoded event.
-func (rtm *RTM) handleRawEvent(rawEvent json.RawMessage) {
+// returns the event type of the message.
+func (rtm *RTM) handleRawEvent(rawEvent json.RawMessage) string {
 	event := &Event{}
 	err := json.Unmarshal(rawEvent, event)
 	if err != nil {
 		rtm.IncomingEvents <- RTMEvent{"unmarshalling_error", &UnmarshallingErrorEvent{err}}
-		return
+		return ""
 	}
+
 	switch event.Type {
-	case "":
+	case rtmEventTypeAck:
 		rtm.handleAck(rawEvent)
-	case "hello":
+	case rtmEventTypeHello:
 		rtm.IncomingEvents <- RTMEvent{"hello", &HelloEvent{}}
-	case "pong":
+	case rtmEventTypePong:
 		rtm.handlePong(rawEvent)
-	case "desktop_notification":
+	case rtmEventTypeGoodbye:
+		// just return the event type up for goodbye, will be handled by caller.
+	case rtmEventTypeDesktopNotification:
 		rtm.Debugln("Received desktop notification, ignoring")
 	default:
 		rtm.handleEvent(event.Type, rawEvent)
 	}
+
+	return event.Type
 }
 
 // handleAck handles an incoming 'ACK' message.
@@ -331,7 +382,13 @@ func (rtm *RTM) handleAck(event json.RawMessage) {
 	if ack.Ok {
 		rtm.IncomingEvents <- RTMEvent{"ack", ack}
 	} else if ack.RTMResponse.Error != nil {
-		rtm.IncomingEvents <- RTMEvent{"ack_error", &AckErrorEvent{ack.Error}}
+		// As there is no documentation for RTM error-codes, this
+		// identification of a rate-limit warning is very brittle.
+		if ack.RTMResponse.Error.Code == -1 && ack.RTMResponse.Error.Msg == "slow down, too many messages..." {
+			rtm.IncomingEvents <- RTMEvent{"ack_error", &RateLimitEvent{}}
+		} else {
+			rtm.IncomingEvents <- RTMEvent{"ack_error", &AckErrorEvent{ack.Error}}
+		}
 	} else {
 		rtm.IncomingEvents <- RTMEvent{"ack_error", &AckErrorEvent{fmt.Errorf("ack decode failure")}}
 	}
@@ -341,19 +398,20 @@ func (rtm *RTM) handleAck(event json.RawMessage) {
 // a previously sent 'PING' message. This is then used to compute the
 // connection's latency.
 func (rtm *RTM) handlePong(event json.RawMessage) {
-	pong := &Pong{}
-	if err := json.Unmarshal(event, pong); err != nil {
-		rtm.Debugln("RTM Error unmarshalling 'pong' event:", err)
+	var (
+		p Pong
+	)
+
+	rtm.resetDeadman()
+
+	if err := json.Unmarshal(event, &p); err != nil {
+		logger.Println("RTM Error unmarshalling 'pong' event:", err)
 		rtm.Debugln(" -> Erroneous 'ping' event:", string(event))
 		return
 	}
-	if pingTime, exists := rtm.pings[pong.ReplyTo]; exists {
-		latency := time.Since(pingTime)
-		rtm.IncomingEvents <- RTMEvent{"latency_report", &LatencyReport{Value: latency}}
-		delete(rtm.pings, pong.ReplyTo)
-	} else {
-		rtm.Debugln("RTM Error - unmatched 'pong' event:", string(event))
-	}
+
+	latency := time.Since(time.Unix(p.Timestamp, 0))
+	rtm.IncomingEvents <- RTMEvent{"latency_report", &LatencyReport{Value: latency}}
 }
 
 // handleEvent is the "default" response to an event that does not have a
@@ -363,7 +421,7 @@ func (rtm *RTM) handlePong(event json.RawMessage) {
 // correct struct then this sends an UnmarshallingErrorEvent to the
 // IncomingEvents channel.
 func (rtm *RTM) handleEvent(typeStr string, event json.RawMessage) {
-	v, exists := eventMapping[typeStr]
+	v, exists := EventMapping[typeStr]
 	if !exists {
 		rtm.Debugf("RTM Error, received unmapped event %q: %s\n", typeStr, string(event))
 		err := fmt.Errorf("RTM Error: Received unmapped event %q: %s\n", typeStr, string(event))
@@ -382,10 +440,10 @@ func (rtm *RTM) handleEvent(typeStr string, event json.RawMessage) {
 	rtm.IncomingEvents <- RTMEvent{typeStr, recvEvent}
 }
 
-// eventMapping holds a mapping of event names to their corresponding struct
+// EventMapping holds a mapping of event names to their corresponding struct
 // implementations. The structs should be instances of the unmarshalling
 // target for the matching event type.
-var eventMapping = map[string]interface{}{
+var EventMapping = map[string]interface{}{
 	"message":         MessageEvent{},
 	"presence_change": PresenceChangeEvent{},
 	"user_typing":     UserTypingEvent{},
@@ -463,4 +521,7 @@ var eventMapping = map[string]interface{}{
 	"accounts_changed": AccountsChangedEvent{},
 
 	"reconnect_url": ReconnectUrlEvent{},
+
+	"member_joined_channel": MemberJoinedChannelEvent{},
+	"member_left_channel":   MemberLeftChannelEvent{},
 }
diff --git a/vendor/github.com/nlopes/slack/websocket_misc.go b/vendor/github.com/nlopes/slack/websocket_misc.go
index ad283ea1..16f48c74 100644
--- a/vendor/github.com/nlopes/slack/websocket_misc.go
+++ b/vendor/github.com/nlopes/slack/websocket_misc.go
@@ -80,7 +80,7 @@ type EmojiChangedEvent struct {
 	SubType        string   `json:"subtype"`
 	Name           string   `json:"name"`
 	Names          []string `json:"names"`
-	Value          string   `json:"value"` 
+	Value          string   `json:"value"`
 	EventTimestamp string   `json:"event_ts"`
 }
 
@@ -119,3 +119,22 @@ type ReconnectUrlEvent struct {
 	Type string `json:"type"`
 	URL  string `json:"url"`
 }
+
+// MemberJoinedChannelEvent, a user joined a public or private channel
+type MemberJoinedChannelEvent struct {
+	Type        string `json:"type"`
+	User        string `json:"user"`
+	Channel     string `json:"channel"`
+	ChannelType string `json:"channel_type"`
+	Team        string `json:"team"`
+	Inviter     string `json:"inviter"`
+}
+
+// MemberJoinedChannelEvent, a user left a public or private channel
+type MemberLeftChannelEvent struct {
+	Type        string `json:"type"`
+	User        string `json:"user"`
+	Channel     string `json:"channel"`
+	ChannelType string `json:"channel_type"`
+	Team        string `json:"team"`
+}
diff --git a/vendor/github.com/nlopes/slack/websocket_proxy.go b/vendor/github.com/nlopes/slack/websocket_proxy.go
deleted file mode 100644
index 27f1cf99..00000000
--- a/vendor/github.com/nlopes/slack/websocket_proxy.go
+++ /dev/null
@@ -1,82 +0,0 @@
-package slack
-
-import (
-	"crypto/tls"
-	"errors"
-	"net"
-	"net/http"
-	"net/http/httputil"
-	"net/url"
-	"os"
-	"strings"
-
-	"golang.org/x/net/websocket"
-)
-
-// Taken and reworked from: https://gist.github.com/madmo/8548738
-func websocketHTTPConnect(proxy, urlString string) (net.Conn, error) {
-	p, err := net.Dial("tcp", proxy)
-	if err != nil {
-		return nil, err
-	}
-
-	turl, err := url.Parse(urlString)
-	if err != nil {
-		return nil, err
-	}
-
-	req := http.Request{
-		Method: "CONNECT",
-		URL:    &url.URL{},
-		Host:   turl.Host,
-	}
-
-	cc := httputil.NewProxyClientConn(p, nil)
-	if _, err := cc.Do(&req); err != nil {
-		return nil, err
-	}
-
-	rwc, _ := cc.Hijack()
-
-	return rwc, nil
-}
-
-func websocketProxyDial(urlString, origin string) (ws *websocket.Conn, err error) {
-	if os.Getenv("HTTP_PROXY") == "" {
-		return websocket.Dial(urlString, "", origin)
-	}
-
-	purl, err := url.Parse(os.Getenv("HTTP_PROXY"))
-	if err != nil {
-		return nil, err
-	}
-
-	config, err := websocket.NewConfig(urlString, origin)
-	if err != nil {
-		return nil, err
-	}
-
-	client, err := websocketHTTPConnect(purl.Host, urlString)
-	if err != nil {
-		return nil, err
-	}
-
-	switch config.Location.Scheme {
-	case "ws":
-	case "wss":
-		tlsClient := tls.Client(client, &tls.Config{
-			ServerName: strings.Split(config.Location.Host, ":")[0],
-		})
-		err := tlsClient.Handshake()
-		if err != nil {
-			tlsClient.Close()
-			return nil, err
-		}
-		client = tlsClient
-
-	default:
-		return nil, errors.New("invalid websocket schema")
-	}
-
-	return websocket.NewClient(config, client)
-}
diff --git a/vendor/github.com/pkg/errors/.gitignore b/vendor/github.com/pkg/errors/.gitignore
new file mode 100644
index 00000000..daf913b1
--- /dev/null
+++ b/vendor/github.com/pkg/errors/.gitignore
@@ -0,0 +1,24 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
diff --git a/vendor/github.com/pkg/errors/.travis.yml b/vendor/github.com/pkg/errors/.travis.yml
new file mode 100644
index 00000000..588ceca1
--- /dev/null
+++ b/vendor/github.com/pkg/errors/.travis.yml
@@ -0,0 +1,11 @@
+language: go
+go_import_path: github.com/pkg/errors
+go:
+  - 1.4.3
+  - 1.5.4
+  - 1.6.2
+  - 1.7.1
+  - tip
+
+script:
+  - go test -v ./...
diff --git a/vendor/github.com/pkg/errors/LICENSE b/vendor/github.com/pkg/errors/LICENSE
new file mode 100644
index 00000000..835ba3e7
--- /dev/null
+++ b/vendor/github.com/pkg/errors/LICENSE
@@ -0,0 +1,23 @@
+Copyright (c) 2015, Dave Cheney <dave@cheney.net>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/pkg/errors/README.md b/vendor/github.com/pkg/errors/README.md
new file mode 100644
index 00000000..273db3c9
--- /dev/null
+++ b/vendor/github.com/pkg/errors/README.md
@@ -0,0 +1,52 @@
+# errors [![Travis-CI](https://travis-ci.org/pkg/errors.svg)](https://travis-ci.org/pkg/errors) [![AppVeyor](https://ci.appveyor.com/api/projects/status/b98mptawhudj53ep/branch/master?svg=true)](https://ci.appveyor.com/project/davecheney/errors/branch/master) [![GoDoc](https://godoc.org/github.com/pkg/errors?status.svg)](http://godoc.org/github.com/pkg/errors) [![Report card](https://goreportcard.com/badge/github.com/pkg/errors)](https://goreportcard.com/report/github.com/pkg/errors)
+
+Package errors provides simple error handling primitives.
+
+`go get github.com/pkg/errors`
+
+The traditional error handling idiom in Go is roughly akin to
+```go
+if err != nil {
+        return err
+}
+```
+which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.
+
+## Adding context to an error
+
+The errors.Wrap function returns a new error that adds context to the original error. For example
+```go
+_, err := ioutil.ReadAll(r)
+if err != nil {
+        return errors.Wrap(err, "read failed")
+}
+```
+## Retrieving the cause of an error
+
+Using `errors.Wrap` constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by `errors.Cause`.
+```go
+type causer interface {
+        Cause() error
+}
+```
+`errors.Cause` will recursively retrieve the topmost error which does not implement `causer`, which is assumed to be the original cause. For example:
+```go
+switch err := errors.Cause(err).(type) {
+case *MyError:
+        // handle specifically
+default:
+        // unknown error
+}
+```
+
+[Read the package documentation for more information](https://godoc.org/github.com/pkg/errors).
+
+## Contributing
+
+We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.
+
+Before proposing a change, please discuss your change by raising an issue.
+
+## Licence
+
+BSD-2-Clause
diff --git a/vendor/github.com/pkg/errors/appveyor.yml b/vendor/github.com/pkg/errors/appveyor.yml
new file mode 100644
index 00000000..a932eade
--- /dev/null
+++ b/vendor/github.com/pkg/errors/appveyor.yml
@@ -0,0 +1,32 @@
+version: build-{build}.{branch}
+
+clone_folder: C:\gopath\src\github.com\pkg\errors
+shallow_clone: true # for startup speed
+
+environment:
+  GOPATH: C:\gopath
+
+platform:
+  - x64
+
+# http://www.appveyor.com/docs/installed-software
+install:
+  # some helpful output for debugging builds
+  - go version
+  - go env
+  # pre-installed MinGW at C:\MinGW is 32bit only
+  # but MSYS2 at C:\msys64 has mingw64
+  - set PATH=C:\msys64\mingw64\bin;%PATH%
+  - gcc --version
+  - g++ --version
+
+build_script:
+  - go install -v ./...
+
+test_script:
+  - set PATH=C:\gopath\bin;%PATH%
+  - go test -v ./...
+
+#artifacts:
+#  - path: '%GOPATH%\bin\*.exe'
+deploy: off
diff --git a/vendor/github.com/pkg/errors/errors.go b/vendor/github.com/pkg/errors/errors.go
new file mode 100644
index 00000000..842ee804
--- /dev/null
+++ b/vendor/github.com/pkg/errors/errors.go
@@ -0,0 +1,269 @@
+// Package errors provides simple error handling primitives.
+//
+// The traditional error handling idiom in Go is roughly akin to
+//
+//     if err != nil {
+//             return err
+//     }
+//
+// which applied recursively up the call stack results in error reports
+// without context or debugging information. The errors package allows
+// programmers to add context to the failure path in their code in a way
+// that does not destroy the original value of the error.
+//
+// Adding context to an error
+//
+// The errors.Wrap function returns a new error that adds context to the
+// original error by recording a stack trace at the point Wrap is called,
+// and the supplied message. For example
+//
+//     _, err := ioutil.ReadAll(r)
+//     if err != nil {
+//             return errors.Wrap(err, "read failed")
+//     }
+//
+// If additional control is required the errors.WithStack and errors.WithMessage
+// functions destructure errors.Wrap into its component operations of annotating
+// an error with a stack trace and an a message, respectively.
+//
+// Retrieving the cause of an error
+//
+// Using errors.Wrap constructs a stack of errors, adding context to the
+// preceding error. Depending on the nature of the error it may be necessary
+// to reverse the operation of errors.Wrap to retrieve the original error
+// for inspection. Any error value which implements this interface
+//
+//     type causer interface {
+//             Cause() error
+//     }
+//
+// can be inspected by errors.Cause. errors.Cause will recursively retrieve
+// the topmost error which does not implement causer, which is assumed to be
+// the original cause. For example:
+//
+//     switch err := errors.Cause(err).(type) {
+//     case *MyError:
+//             // handle specifically
+//     default:
+//             // unknown error
+//     }
+//
+// causer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// Formatted printing of errors
+//
+// All error values returned from this package implement fmt.Formatter and can
+// be formatted by the fmt package. The following verbs are supported
+//
+//     %s    print the error. If the error has a Cause it will be
+//           printed recursively
+//     %v    see %s
+//     %+v   extended format. Each Frame of the error's StackTrace will
+//           be printed in detail.
+//
+// Retrieving the stack trace of an error or wrapper
+//
+// New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
+// invoked. This information can be retrieved with the following interface.
+//
+//     type stackTracer interface {
+//             StackTrace() errors.StackTrace
+//     }
+//
+// Where errors.StackTrace is defined as
+//
+//     type StackTrace []Frame
+//
+// The Frame type represents a call site in the stack trace. Frame supports
+// the fmt.Formatter interface that can be used for printing information about
+// the stack trace of this error. For example:
+//
+//     if err, ok := err.(stackTracer); ok {
+//             for _, f := range err.StackTrace() {
+//                     fmt.Printf("%+s:%d", f)
+//             }
+//     }
+//
+// stackTracer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// See the documentation for Frame.Format for more details.
+package errors
+
+import (
+	"fmt"
+	"io"
+)
+
+// New returns an error with the supplied message.
+// New also records the stack trace at the point it was called.
+func New(message string) error {
+	return &fundamental{
+		msg:   message,
+		stack: callers(),
+	}
+}
+
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+// Errorf also records the stack trace at the point it was called.
+func Errorf(format string, args ...interface{}) error {
+	return &fundamental{
+		msg:   fmt.Sprintf(format, args...),
+		stack: callers(),
+	}
+}
+
+// fundamental is an error that has a message and a stack, but no caller.
+type fundamental struct {
+	msg string
+	*stack
+}
+
+func (f *fundamental) Error() string { return f.msg }
+
+func (f *fundamental) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			io.WriteString(s, f.msg)
+			f.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, f.msg)
+	case 'q':
+		fmt.Fprintf(s, "%q", f.msg)
+	}
+}
+
+// WithStack annotates err with a stack trace at the point WithStack was called.
+// If err is nil, WithStack returns nil.
+func WithStack(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+type withStack struct {
+	error
+	*stack
+}
+
+func (w *withStack) Cause() error { return w.error }
+
+func (w *withStack) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v", w.Cause())
+			w.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, w.Error())
+	case 'q':
+		fmt.Fprintf(s, "%q", w.Error())
+	}
+}
+
+// Wrap returns an error annotating err with a stack trace
+// at the point Wrap is called, and the supplied message.
+// If err is nil, Wrap returns nil.
+func Wrap(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   message,
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// Wrapf returns an error annotating err with a stack trace
+// at the point Wrapf is call, and the format specifier.
+// If err is nil, Wrapf returns nil.
+func Wrapf(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   fmt.Sprintf(format, args...),
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// WithMessage annotates err with a new message.
+// If err is nil, WithMessage returns nil.
+func WithMessage(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	return &withMessage{
+		cause: err,
+		msg:   message,
+	}
+}
+
+type withMessage struct {
+	cause error
+	msg   string
+}
+
+func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() }
+func (w *withMessage) Cause() error  { return w.cause }
+
+func (w *withMessage) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v\n", w.Cause())
+			io.WriteString(s, w.msg)
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		io.WriteString(s, w.Error())
+	}
+}
+
+// Cause returns the underlying cause of the error, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+//
+// If the error does not implement Cause, the original error will
+// be returned. If the error is nil, nil will be returned without further
+// investigation.
+func Cause(err error) error {
+	type causer interface {
+		Cause() error
+	}
+
+	for err != nil {
+		cause, ok := err.(causer)
+		if !ok {
+			break
+		}
+		err = cause.Cause()
+	}
+	return err
+}
diff --git a/vendor/github.com/pkg/errors/stack.go b/vendor/github.com/pkg/errors/stack.go
new file mode 100644
index 00000000..6b1f2891
--- /dev/null
+++ b/vendor/github.com/pkg/errors/stack.go
@@ -0,0 +1,178 @@
+package errors
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"runtime"
+	"strings"
+)
+
+// Frame represents a program counter inside a stack frame.
+type Frame uintptr
+
+// pc returns the program counter for this frame;
+// multiple frames may have the same PC value.
+func (f Frame) pc() uintptr { return uintptr(f) - 1 }
+
+// file returns the full path to the file that contains the
+// function for this Frame's pc.
+func (f Frame) file() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	file, _ := fn.FileLine(f.pc())
+	return file
+}
+
+// line returns the line number of source code of the
+// function for this Frame's pc.
+func (f Frame) line() int {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return 0
+	}
+	_, line := fn.FileLine(f.pc())
+	return line
+}
+
+// Format formats the frame according to the fmt.Formatter interface.
+//
+//    %s    source file
+//    %d    source line
+//    %n    function name
+//    %v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+s   path of source file relative to the compile time GOPATH
+//    %+v   equivalent to %+s:%d
+func (f Frame) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 's':
+		switch {
+		case s.Flag('+'):
+			pc := f.pc()
+			fn := runtime.FuncForPC(pc)
+			if fn == nil {
+				io.WriteString(s, "unknown")
+			} else {
+				file, _ := fn.FileLine(pc)
+				fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
+			}
+		default:
+			io.WriteString(s, path.Base(f.file()))
+		}
+	case 'd':
+		fmt.Fprintf(s, "%d", f.line())
+	case 'n':
+		name := runtime.FuncForPC(f.pc()).Name()
+		io.WriteString(s, funcname(name))
+	case 'v':
+		f.Format(s, 's')
+		io.WriteString(s, ":")
+		f.Format(s, 'd')
+	}
+}
+
+// StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
+type StackTrace []Frame
+
+func (st StackTrace) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case s.Flag('+'):
+			for _, f := range st {
+				fmt.Fprintf(s, "\n%+v", f)
+			}
+		case s.Flag('#'):
+			fmt.Fprintf(s, "%#v", []Frame(st))
+		default:
+			fmt.Fprintf(s, "%v", []Frame(st))
+		}
+	case 's':
+		fmt.Fprintf(s, "%s", []Frame(st))
+	}
+}
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+func (s *stack) Format(st fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case st.Flag('+'):
+			for _, pc := range *s {
+				f := Frame(pc)
+				fmt.Fprintf(st, "\n%+v", f)
+			}
+		}
+	}
+}
+
+func (s *stack) StackTrace() StackTrace {
+	f := make([]Frame, len(*s))
+	for i := 0; i < len(f); i++ {
+		f[i] = Frame((*s)[i])
+	}
+	return f
+}
+
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(3, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// funcname removes the path prefix component of a function's name reported by func.Name().
+func funcname(name string) string {
+	i := strings.LastIndex(name, "/")
+	name = name[i+1:]
+	i = strings.Index(name, ".")
+	return name[i+1:]
+}
+
+func trimGOPATH(name, file string) string {
+	// Here we want to get the source file path relative to the compile time
+	// GOPATH. As of Go 1.6.x there is no direct way to know the compiled
+	// GOPATH at runtime, but we can infer the number of path segments in the
+	// GOPATH. We note that fn.Name() returns the function name qualified by
+	// the import path, which does not include the GOPATH. Thus we can trim
+	// segments from the beginning of the file path until the number of path
+	// separators remaining is one more than the number of path separators in
+	// the function name. For example, given:
+	//
+	//    GOPATH     /home/user
+	//    file       /home/user/src/pkg/sub/file.go
+	//    fn.Name()  pkg/sub.Type.Method
+	//
+	// We want to produce:
+	//
+	//    pkg/sub/file.go
+	//
+	// From this we can easily see that fn.Name() has one less path separator
+	// than our desired output. We count separators from the end of the file
+	// path until it finds two more than in the function name and then move
+	// one character forward to preserve the initial path segment without a
+	// leading separator.
+	const sep = "/"
+	goal := strings.Count(name, sep) + 2
+	i := len(file)
+	for n := 0; n < goal; n++ {
+		i = strings.LastIndex(file[:i], sep)
+		if i == -1 {
+			// not enough separators found, set i so that the slice expression
+			// below leaves file unmodified
+			i = -len(sep)
+			break
+		}
+	}
+	// get back to 0 or trim the leading separator
+	file = file[i+len(sep):]
+	return file
+}
diff --git a/vendor/golang.org/x/net/AUTHORS b/vendor/golang.org/x/net/AUTHORS
deleted file mode 100644
index 15167cd7..00000000
--- a/vendor/golang.org/x/net/AUTHORS
+++ /dev/null
@@ -1,3 +0,0 @@
-# This source code refers to The Go Authors for copyright purposes.
-# The master list of authors is in the main Go distribution,
-# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/golang.org/x/net/CONTRIBUTORS b/vendor/golang.org/x/net/CONTRIBUTORS
deleted file mode 100644
index 1c4577e9..00000000
--- a/vendor/golang.org/x/net/CONTRIBUTORS
+++ /dev/null
@@ -1,3 +0,0 @@
-# This source code was written by the Go contributors.
-# The master list of contributors is in the main Go distribution,
-# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/golang.org/x/net/LICENSE b/vendor/golang.org/x/net/LICENSE
deleted file mode 100644
index 6a66aea5..00000000
--- a/vendor/golang.org/x/net/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-Copyright (c) 2009 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/golang.org/x/net/PATENTS b/vendor/golang.org/x/net/PATENTS
deleted file mode 100644
index 73309904..00000000
--- a/vendor/golang.org/x/net/PATENTS
+++ /dev/null
@@ -1,22 +0,0 @@
-Additional IP Rights Grant (Patents)
-
-"This implementation" means the copyrightable works distributed by
-Google as part of the Go project.
-
-Google hereby grants to You a perpetual, worldwide, non-exclusive,
-no-charge, royalty-free, irrevocable (except as stated in this section)
-patent license to make, have made, use, offer to sell, sell, import,
-transfer and otherwise run, modify and propagate the contents of this
-implementation of Go, where such license applies only to those patent
-claims, both currently owned or controlled by Google and acquired in
-the future, licensable by Google that are necessarily infringed by this
-implementation of Go.  This grant does not include claims that would be
-infringed only as a consequence of further modification of this
-implementation.  If you or your agent or exclusive licensee institute or
-order or agree to the institution of patent litigation against any
-entity (including a cross-claim or counterclaim in a lawsuit) alleging
-that this implementation of Go or any code incorporated within this
-implementation of Go constitutes direct or contributory patent
-infringement, or inducement of patent infringement, then any patent
-rights granted to you under this License for this implementation of Go
-shall terminate as of the date such litigation is filed.
diff --git a/vendor/golang.org/x/net/websocket/client.go b/vendor/golang.org/x/net/websocket/client.go
deleted file mode 100644
index 69a4ac7e..00000000
--- a/vendor/golang.org/x/net/websocket/client.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package websocket
-
-import (
-	"bufio"
-	"io"
-	"net"
-	"net/http"
-	"net/url"
-)
-
-// DialError is an error that occurs while dialling a websocket server.
-type DialError struct {
-	*Config
-	Err error
-}
-
-func (e *DialError) Error() string {
-	return "websocket.Dial " + e.Config.Location.String() + ": " + e.Err.Error()
-}
-
-// NewConfig creates a new WebSocket config for client connection.
-func NewConfig(server, origin string) (config *Config, err error) {
-	config = new(Config)
-	config.Version = ProtocolVersionHybi13
-	config.Location, err = url.ParseRequestURI(server)
-	if err != nil {
-		return
-	}
-	config.Origin, err = url.ParseRequestURI(origin)
-	if err != nil {
-		return
-	}
-	config.Header = http.Header(make(map[string][]string))
-	return
-}
-
-// NewClient creates a new WebSocket client connection over rwc.
-func NewClient(config *Config, rwc io.ReadWriteCloser) (ws *Conn, err error) {
-	br := bufio.NewReader(rwc)
-	bw := bufio.NewWriter(rwc)
-	err = hybiClientHandshake(config, br, bw)
-	if err != nil {
-		return
-	}
-	buf := bufio.NewReadWriter(br, bw)
-	ws = newHybiClientConn(config, buf, rwc)
-	return
-}
-
-// Dial opens a new client connection to a WebSocket.
-func Dial(url_, protocol, origin string) (ws *Conn, err error) {
-	config, err := NewConfig(url_, origin)
-	if err != nil {
-		return nil, err
-	}
-	if protocol != "" {
-		config.Protocol = []string{protocol}
-	}
-	return DialConfig(config)
-}
-
-var portMap = map[string]string{
-	"ws":  "80",
-	"wss": "443",
-}
-
-func parseAuthority(location *url.URL) string {
-	if _, ok := portMap[location.Scheme]; ok {
-		if _, _, err := net.SplitHostPort(location.Host); err != nil {
-			return net.JoinHostPort(location.Host, portMap[location.Scheme])
-		}
-	}
-	return location.Host
-}
-
-// DialConfig opens a new client connection to a WebSocket with a config.
-func DialConfig(config *Config) (ws *Conn, err error) {
-	var client net.Conn
-	if config.Location == nil {
-		return nil, &DialError{config, ErrBadWebSocketLocation}
-	}
-	if config.Origin == nil {
-		return nil, &DialError{config, ErrBadWebSocketOrigin}
-	}
-	dialer := config.Dialer
-	if dialer == nil {
-		dialer = &net.Dialer{}
-	}
-	client, err = dialWithDialer(dialer, config)
-	if err != nil {
-		goto Error
-	}
-	ws, err = NewClient(config, client)
-	if err != nil {
-		client.Close()
-		goto Error
-	}
-	return
-
-Error:
-	return nil, &DialError{config, err}
-}
diff --git a/vendor/golang.org/x/net/websocket/dial.go b/vendor/golang.org/x/net/websocket/dial.go
deleted file mode 100644
index 2dab943a..00000000
--- a/vendor/golang.org/x/net/websocket/dial.go
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package websocket
-
-import (
-	"crypto/tls"
-	"net"
-)
-
-func dialWithDialer(dialer *net.Dialer, config *Config) (conn net.Conn, err error) {
-	switch config.Location.Scheme {
-	case "ws":
-		conn, err = dialer.Dial("tcp", parseAuthority(config.Location))
-
-	case "wss":
-		conn, err = tls.DialWithDialer(dialer, "tcp", parseAuthority(config.Location), config.TlsConfig)
-
-	default:
-		err = ErrBadScheme
-	}
-	return
-}
diff --git a/vendor/golang.org/x/net/websocket/hybi.go b/vendor/golang.org/x/net/websocket/hybi.go
deleted file mode 100644
index 8cffdd16..00000000
--- a/vendor/golang.org/x/net/websocket/hybi.go
+++ /dev/null
@@ -1,583 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package websocket
-
-// This file implements a protocol of hybi draft.
-// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17
-
-import (
-	"bufio"
-	"bytes"
-	"crypto/rand"
-	"crypto/sha1"
-	"encoding/base64"
-	"encoding/binary"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"net/http"
-	"net/url"
-	"strings"
-)
-
-const (
-	websocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
-
-	closeStatusNormal            = 1000
-	closeStatusGoingAway         = 1001
-	closeStatusProtocolError     = 1002
-	closeStatusUnsupportedData   = 1003
-	closeStatusFrameTooLarge     = 1004
-	closeStatusNoStatusRcvd      = 1005
-	closeStatusAbnormalClosure   = 1006
-	closeStatusBadMessageData    = 1007
-	closeStatusPolicyViolation   = 1008
-	closeStatusTooBigData        = 1009
-	closeStatusExtensionMismatch = 1010
-
-	maxControlFramePayloadLength = 125
-)
-
-var (
-	ErrBadMaskingKey         = &ProtocolError{"bad masking key"}
-	ErrBadPongMessage        = &ProtocolError{"bad pong message"}
-	ErrBadClosingStatus      = &ProtocolError{"bad closing status"}
-	ErrUnsupportedExtensions = &ProtocolError{"unsupported extensions"}
-	ErrNotImplemented        = &ProtocolError{"not implemented"}
-
-	handshakeHeader = map[string]bool{
-		"Host":                   true,
-		"Upgrade":                true,
-		"Connection":             true,
-		"Sec-Websocket-Key":      true,
-		"Sec-Websocket-Origin":   true,
-		"Sec-Websocket-Version":  true,
-		"Sec-Websocket-Protocol": true,
-		"Sec-Websocket-Accept":   true,
-	}
-)
-
-// A hybiFrameHeader is a frame header as defined in hybi draft.
-type hybiFrameHeader struct {
-	Fin        bool
-	Rsv        [3]bool
-	OpCode     byte
-	Length     int64
-	MaskingKey []byte
-
-	data *bytes.Buffer
-}
-
-// A hybiFrameReader is a reader for hybi frame.
-type hybiFrameReader struct {
-	reader io.Reader
-
-	header hybiFrameHeader
-	pos    int64
-	length int
-}
-
-func (frame *hybiFrameReader) Read(msg []byte) (n int, err error) {
-	n, err = frame.reader.Read(msg)
-	if frame.header.MaskingKey != nil {
-		for i := 0; i < n; i++ {
-			msg[i] = msg[i] ^ frame.header.MaskingKey[frame.pos%4]
-			frame.pos++
-		}
-	}
-	return n, err
-}
-
-func (frame *hybiFrameReader) PayloadType() byte { return frame.header.OpCode }
-
-func (frame *hybiFrameReader) HeaderReader() io.Reader {
-	if frame.header.data == nil {
-		return nil
-	}
-	if frame.header.data.Len() == 0 {
-		return nil
-	}
-	return frame.header.data
-}
-
-func (frame *hybiFrameReader) TrailerReader() io.Reader { return nil }
-
-func (frame *hybiFrameReader) Len() (n int) { return frame.length }
-
-// A hybiFrameReaderFactory creates new frame reader based on its frame type.
-type hybiFrameReaderFactory struct {
-	*bufio.Reader
-}
-
-// NewFrameReader reads a frame header from the connection, and creates new reader for the frame.
-// See Section 5.2 Base Framing protocol for detail.
-// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17#section-5.2
-func (buf hybiFrameReaderFactory) NewFrameReader() (frame frameReader, err error) {
-	hybiFrame := new(hybiFrameReader)
-	frame = hybiFrame
-	var header []byte
-	var b byte
-	// First byte. FIN/RSV1/RSV2/RSV3/OpCode(4bits)
-	b, err = buf.ReadByte()
-	if err != nil {
-		return
-	}
-	header = append(header, b)
-	hybiFrame.header.Fin = ((header[0] >> 7) & 1) != 0
-	for i := 0; i < 3; i++ {
-		j := uint(6 - i)
-		hybiFrame.header.Rsv[i] = ((header[0] >> j) & 1) != 0
-	}
-	hybiFrame.header.OpCode = header[0] & 0x0f
-
-	// Second byte. Mask/Payload len(7bits)
-	b, err = buf.ReadByte()
-	if err != nil {
-		return
-	}
-	header = append(header, b)
-	mask := (b & 0x80) != 0
-	b &= 0x7f
-	lengthFields := 0
-	switch {
-	case b <= 125: // Payload length 7bits.
-		hybiFrame.header.Length = int64(b)
-	case b == 126: // Payload length 7+16bits
-		lengthFields = 2
-	case b == 127: // Payload length 7+64bits
-		lengthFields = 8
-	}
-	for i := 0; i < lengthFields; i++ {
-		b, err = buf.ReadByte()
-		if err != nil {
-			return
-		}
-		if lengthFields == 8 && i == 0 { // MSB must be zero when 7+64 bits
-			b &= 0x7f
-		}
-		header = append(header, b)
-		hybiFrame.header.Length = hybiFrame.header.Length*256 + int64(b)
-	}
-	if mask {
-		// Masking key. 4 bytes.
-		for i := 0; i < 4; i++ {
-			b, err = buf.ReadByte()
-			if err != nil {
-				return
-			}
-			header = append(header, b)
-			hybiFrame.header.MaskingKey = append(hybiFrame.header.MaskingKey, b)
-		}
-	}
-	hybiFrame.reader = io.LimitReader(buf.Reader, hybiFrame.header.Length)
-	hybiFrame.header.data = bytes.NewBuffer(header)
-	hybiFrame.length = len(header) + int(hybiFrame.header.Length)
-	return
-}
-
-// A HybiFrameWriter is a writer for hybi frame.
-type hybiFrameWriter struct {
-	writer *bufio.Writer
-
-	header *hybiFrameHeader
-}
-
-func (frame *hybiFrameWriter) Write(msg []byte) (n int, err error) {
-	var header []byte
-	var b byte
-	if frame.header.Fin {
-		b |= 0x80
-	}
-	for i := 0; i < 3; i++ {
-		if frame.header.Rsv[i] {
-			j := uint(6 - i)
-			b |= 1 << j
-		}
-	}
-	b |= frame.header.OpCode
-	header = append(header, b)
-	if frame.header.MaskingKey != nil {
-		b = 0x80
-	} else {
-		b = 0
-	}
-	lengthFields := 0
-	length := len(msg)
-	switch {
-	case length <= 125:
-		b |= byte(length)
-	case length < 65536:
-		b |= 126
-		lengthFields = 2
-	default:
-		b |= 127
-		lengthFields = 8
-	}
-	header = append(header, b)
-	for i := 0; i < lengthFields; i++ {
-		j := uint((lengthFields - i - 1) * 8)
-		b = byte((length >> j) & 0xff)
-		header = append(header, b)
-	}
-	if frame.header.MaskingKey != nil {
-		if len(frame.header.MaskingKey) != 4 {
-			return 0, ErrBadMaskingKey
-		}
-		header = append(header, frame.header.MaskingKey...)
-		frame.writer.Write(header)
-		data := make([]byte, length)
-		for i := range data {
-			data[i] = msg[i] ^ frame.header.MaskingKey[i%4]
-		}
-		frame.writer.Write(data)
-		err = frame.writer.Flush()
-		return length, err
-	}
-	frame.writer.Write(header)
-	frame.writer.Write(msg)
-	err = frame.writer.Flush()
-	return length, err
-}
-
-func (frame *hybiFrameWriter) Close() error { return nil }
-
-type hybiFrameWriterFactory struct {
-	*bufio.Writer
-	needMaskingKey bool
-}
-
-func (buf hybiFrameWriterFactory) NewFrameWriter(payloadType byte) (frame frameWriter, err error) {
-	frameHeader := &hybiFrameHeader{Fin: true, OpCode: payloadType}
-	if buf.needMaskingKey {
-		frameHeader.MaskingKey, err = generateMaskingKey()
-		if err != nil {
-			return nil, err
-		}
-	}
-	return &hybiFrameWriter{writer: buf.Writer, header: frameHeader}, nil
-}
-
-type hybiFrameHandler struct {
-	conn        *Conn
-	payloadType byte
-}
-
-func (handler *hybiFrameHandler) HandleFrame(frame frameReader) (frameReader, error) {
-	if handler.conn.IsServerConn() {
-		// The client MUST mask all frames sent to the server.
-		if frame.(*hybiFrameReader).header.MaskingKey == nil {
-			handler.WriteClose(closeStatusProtocolError)
-			return nil, io.EOF
-		}
-	} else {
-		// The server MUST NOT mask all frames.
-		if frame.(*hybiFrameReader).header.MaskingKey != nil {
-			handler.WriteClose(closeStatusProtocolError)
-			return nil, io.EOF
-		}
-	}
-	if header := frame.HeaderReader(); header != nil {
-		io.Copy(ioutil.Discard, header)
-	}
-	switch frame.PayloadType() {
-	case ContinuationFrame:
-		frame.(*hybiFrameReader).header.OpCode = handler.payloadType
-	case TextFrame, BinaryFrame:
-		handler.payloadType = frame.PayloadType()
-	case CloseFrame:
-		return nil, io.EOF
-	case PingFrame, PongFrame:
-		b := make([]byte, maxControlFramePayloadLength)
-		n, err := io.ReadFull(frame, b)
-		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
-			return nil, err
-		}
-		io.Copy(ioutil.Discard, frame)
-		if frame.PayloadType() == PingFrame {
-			if _, err := handler.WritePong(b[:n]); err != nil {
-				return nil, err
-			}
-		}
-		return nil, nil
-	}
-	return frame, nil
-}
-
-func (handler *hybiFrameHandler) WriteClose(status int) (err error) {
-	handler.conn.wio.Lock()
-	defer handler.conn.wio.Unlock()
-	w, err := handler.conn.frameWriterFactory.NewFrameWriter(CloseFrame)
-	if err != nil {
-		return err
-	}
-	msg := make([]byte, 2)
-	binary.BigEndian.PutUint16(msg, uint16(status))
-	_, err = w.Write(msg)
-	w.Close()
-	return err
-}
-
-func (handler *hybiFrameHandler) WritePong(msg []byte) (n int, err error) {
-	handler.conn.wio.Lock()
-	defer handler.conn.wio.Unlock()
-	w, err := handler.conn.frameWriterFactory.NewFrameWriter(PongFrame)
-	if err != nil {
-		return 0, err
-	}
-	n, err = w.Write(msg)
-	w.Close()
-	return n, err
-}
-
-// newHybiConn creates a new WebSocket connection speaking hybi draft protocol.
-func newHybiConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
-	if buf == nil {
-		br := bufio.NewReader(rwc)
-		bw := bufio.NewWriter(rwc)
-		buf = bufio.NewReadWriter(br, bw)
-	}
-	ws := &Conn{config: config, request: request, buf: buf, rwc: rwc,
-		frameReaderFactory: hybiFrameReaderFactory{buf.Reader},
-		frameWriterFactory: hybiFrameWriterFactory{
-			buf.Writer, request == nil},
-		PayloadType:        TextFrame,
-		defaultCloseStatus: closeStatusNormal}
-	ws.frameHandler = &hybiFrameHandler{conn: ws}
-	return ws
-}
-
-// generateMaskingKey generates a masking key for a frame.
-func generateMaskingKey() (maskingKey []byte, err error) {
-	maskingKey = make([]byte, 4)
-	if _, err = io.ReadFull(rand.Reader, maskingKey); err != nil {
-		return
-	}
-	return
-}
-
-// generateNonce generates a nonce consisting of a randomly selected 16-byte
-// value that has been base64-encoded.
-func generateNonce() (nonce []byte) {
-	key := make([]byte, 16)
-	if _, err := io.ReadFull(rand.Reader, key); err != nil {
-		panic(err)
-	}
-	nonce = make([]byte, 24)
-	base64.StdEncoding.Encode(nonce, key)
-	return
-}
-
-// removeZone removes IPv6 zone identifer from host.
-// E.g., "[fe80::1%en0]:8080" to "[fe80::1]:8080"
-func removeZone(host string) string {
-	if !strings.HasPrefix(host, "[") {
-		return host
-	}
-	i := strings.LastIndex(host, "]")
-	if i < 0 {
-		return host
-	}
-	j := strings.LastIndex(host[:i], "%")
-	if j < 0 {
-		return host
-	}
-	return host[:j] + host[i:]
-}
-
-// getNonceAccept computes the base64-encoded SHA-1 of the concatenation of
-// the nonce ("Sec-WebSocket-Key" value) with the websocket GUID string.
-func getNonceAccept(nonce []byte) (expected []byte, err error) {
-	h := sha1.New()
-	if _, err = h.Write(nonce); err != nil {
-		return
-	}
-	if _, err = h.Write([]byte(websocketGUID)); err != nil {
-		return
-	}
-	expected = make([]byte, 28)
-	base64.StdEncoding.Encode(expected, h.Sum(nil))
-	return
-}
-
-// Client handshake described in draft-ietf-hybi-thewebsocket-protocol-17
-func hybiClientHandshake(config *Config, br *bufio.Reader, bw *bufio.Writer) (err error) {
-	bw.WriteString("GET " + config.Location.RequestURI() + " HTTP/1.1\r\n")
-
-	// According to RFC 6874, an HTTP client, proxy, or other
-	// intermediary must remove any IPv6 zone identifier attached
-	// to an outgoing URI.
-	bw.WriteString("Host: " + removeZone(config.Location.Host) + "\r\n")
-	bw.WriteString("Upgrade: websocket\r\n")
-	bw.WriteString("Connection: Upgrade\r\n")
-	nonce := generateNonce()
-	if config.handshakeData != nil {
-		nonce = []byte(config.handshakeData["key"])
-	}
-	bw.WriteString("Sec-WebSocket-Key: " + string(nonce) + "\r\n")
-	bw.WriteString("Origin: " + strings.ToLower(config.Origin.String()) + "\r\n")
-
-	if config.Version != ProtocolVersionHybi13 {
-		return ErrBadProtocolVersion
-	}
-
-	bw.WriteString("Sec-WebSocket-Version: " + fmt.Sprintf("%d", config.Version) + "\r\n")
-	if len(config.Protocol) > 0 {
-		bw.WriteString("Sec-WebSocket-Protocol: " + strings.Join(config.Protocol, ", ") + "\r\n")
-	}
-	// TODO(ukai): send Sec-WebSocket-Extensions.
-	err = config.Header.WriteSubset(bw, handshakeHeader)
-	if err != nil {
-		return err
-	}
-
-	bw.WriteString("\r\n")
-	if err = bw.Flush(); err != nil {
-		return err
-	}
-
-	resp, err := http.ReadResponse(br, &http.Request{Method: "GET"})
-	if err != nil {
-		return err
-	}
-	if resp.StatusCode != 101 {
-		return ErrBadStatus
-	}
-	if strings.ToLower(resp.Header.Get("Upgrade")) != "websocket" ||
-		strings.ToLower(resp.Header.Get("Connection")) != "upgrade" {
-		return ErrBadUpgrade
-	}
-	expectedAccept, err := getNonceAccept(nonce)
-	if err != nil {
-		return err
-	}
-	if resp.Header.Get("Sec-WebSocket-Accept") != string(expectedAccept) {
-		return ErrChallengeResponse
-	}
-	if resp.Header.Get("Sec-WebSocket-Extensions") != "" {
-		return ErrUnsupportedExtensions
-	}
-	offeredProtocol := resp.Header.Get("Sec-WebSocket-Protocol")
-	if offeredProtocol != "" {
-		protocolMatched := false
-		for i := 0; i < len(config.Protocol); i++ {
-			if config.Protocol[i] == offeredProtocol {
-				protocolMatched = true
-				break
-			}
-		}
-		if !protocolMatched {
-			return ErrBadWebSocketProtocol
-		}
-		config.Protocol = []string{offeredProtocol}
-	}
-
-	return nil
-}
-
-// newHybiClientConn creates a client WebSocket connection after handshake.
-func newHybiClientConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser) *Conn {
-	return newHybiConn(config, buf, rwc, nil)
-}
-
-// A HybiServerHandshaker performs a server handshake using hybi draft protocol.
-type hybiServerHandshaker struct {
-	*Config
-	accept []byte
-}
-
-func (c *hybiServerHandshaker) ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error) {
-	c.Version = ProtocolVersionHybi13
-	if req.Method != "GET" {
-		return http.StatusMethodNotAllowed, ErrBadRequestMethod
-	}
-	// HTTP version can be safely ignored.
-
-	if strings.ToLower(req.Header.Get("Upgrade")) != "websocket" ||
-		!strings.Contains(strings.ToLower(req.Header.Get("Connection")), "upgrade") {
-		return http.StatusBadRequest, ErrNotWebSocket
-	}
-
-	key := req.Header.Get("Sec-Websocket-Key")
-	if key == "" {
-		return http.StatusBadRequest, ErrChallengeResponse
-	}
-	version := req.Header.Get("Sec-Websocket-Version")
-	switch version {
-	case "13":
-		c.Version = ProtocolVersionHybi13
-	default:
-		return http.StatusBadRequest, ErrBadWebSocketVersion
-	}
-	var scheme string
-	if req.TLS != nil {
-		scheme = "wss"
-	} else {
-		scheme = "ws"
-	}
-	c.Location, err = url.ParseRequestURI(scheme + "://" + req.Host + req.URL.RequestURI())
-	if err != nil {
-		return http.StatusBadRequest, err
-	}
-	protocol := strings.TrimSpace(req.Header.Get("Sec-Websocket-Protocol"))
-	if protocol != "" {
-		protocols := strings.Split(protocol, ",")
-		for i := 0; i < len(protocols); i++ {
-			c.Protocol = append(c.Protocol, strings.TrimSpace(protocols[i]))
-		}
-	}
-	c.accept, err = getNonceAccept([]byte(key))
-	if err != nil {
-		return http.StatusInternalServerError, err
-	}
-	return http.StatusSwitchingProtocols, nil
-}
-
-// Origin parses the Origin header in req.
-// If the Origin header is not set, it returns nil and nil.
-func Origin(config *Config, req *http.Request) (*url.URL, error) {
-	var origin string
-	switch config.Version {
-	case ProtocolVersionHybi13:
-		origin = req.Header.Get("Origin")
-	}
-	if origin == "" {
-		return nil, nil
-	}
-	return url.ParseRequestURI(origin)
-}
-
-func (c *hybiServerHandshaker) AcceptHandshake(buf *bufio.Writer) (err error) {
-	if len(c.Protocol) > 0 {
-		if len(c.Protocol) != 1 {
-			// You need choose a Protocol in Handshake func in Server.
-			return ErrBadWebSocketProtocol
-		}
-	}
-	buf.WriteString("HTTP/1.1 101 Switching Protocols\r\n")
-	buf.WriteString("Upgrade: websocket\r\n")
-	buf.WriteString("Connection: Upgrade\r\n")
-	buf.WriteString("Sec-WebSocket-Accept: " + string(c.accept) + "\r\n")
-	if len(c.Protocol) > 0 {
-		buf.WriteString("Sec-WebSocket-Protocol: " + c.Protocol[0] + "\r\n")
-	}
-	// TODO(ukai): send Sec-WebSocket-Extensions.
-	if c.Header != nil {
-		err := c.Header.WriteSubset(buf, handshakeHeader)
-		if err != nil {
-			return err
-		}
-	}
-	buf.WriteString("\r\n")
-	return buf.Flush()
-}
-
-func (c *hybiServerHandshaker) NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
-	return newHybiServerConn(c.Config, buf, rwc, request)
-}
-
-// newHybiServerConn returns a new WebSocket connection speaking hybi draft protocol.
-func newHybiServerConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
-	return newHybiConn(config, buf, rwc, request)
-}
diff --git a/vendor/golang.org/x/net/websocket/server.go b/vendor/golang.org/x/net/websocket/server.go
deleted file mode 100644
index 0895dea1..00000000
--- a/vendor/golang.org/x/net/websocket/server.go
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package websocket
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"net/http"
-)
-
-func newServerConn(rwc io.ReadWriteCloser, buf *bufio.ReadWriter, req *http.Request, config *Config, handshake func(*Config, *http.Request) error) (conn *Conn, err error) {
-	var hs serverHandshaker = &hybiServerHandshaker{Config: config}
-	code, err := hs.ReadHandshake(buf.Reader, req)
-	if err == ErrBadWebSocketVersion {
-		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
-		fmt.Fprintf(buf, "Sec-WebSocket-Version: %s\r\n", SupportedProtocolVersion)
-		buf.WriteString("\r\n")
-		buf.WriteString(err.Error())
-		buf.Flush()
-		return
-	}
-	if err != nil {
-		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
-		buf.WriteString("\r\n")
-		buf.WriteString(err.Error())
-		buf.Flush()
-		return
-	}
-	if handshake != nil {
-		err = handshake(config, req)
-		if err != nil {
-			code = http.StatusForbidden
-			fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
-			buf.WriteString("\r\n")
-			buf.Flush()
-			return
-		}
-	}
-	err = hs.AcceptHandshake(buf.Writer)
-	if err != nil {
-		code = http.StatusBadRequest
-		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
-		buf.WriteString("\r\n")
-		buf.Flush()
-		return
-	}
-	conn = hs.NewServerConn(buf, rwc, req)
-	return
-}
-
-// Server represents a server of a WebSocket.
-type Server struct {
-	// Config is a WebSocket configuration for new WebSocket connection.
-	Config
-
-	// Handshake is an optional function in WebSocket handshake.
-	// For example, you can check, or don't check Origin header.
-	// Another example, you can select config.Protocol.
-	Handshake func(*Config, *http.Request) error
-
-	// Handler handles a WebSocket connection.
-	Handler
-}
-
-// ServeHTTP implements the http.Handler interface for a WebSocket
-func (s Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	s.serveWebSocket(w, req)
-}
-
-func (s Server) serveWebSocket(w http.ResponseWriter, req *http.Request) {
-	rwc, buf, err := w.(http.Hijacker).Hijack()
-	if err != nil {
-		panic("Hijack failed: " + err.Error())
-	}
-	// The server should abort the WebSocket connection if it finds
-	// the client did not send a handshake that matches with protocol
-	// specification.
-	defer rwc.Close()
-	conn, err := newServerConn(rwc, buf, req, &s.Config, s.Handshake)
-	if err != nil {
-		return
-	}
-	if conn == nil {
-		panic("unexpected nil conn")
-	}
-	s.Handler(conn)
-}
-
-// Handler is a simple interface to a WebSocket browser client.
-// It checks if Origin header is valid URL by default.
-// You might want to verify websocket.Conn.Config().Origin in the func.
-// If you use Server instead of Handler, you could call websocket.Origin and
-// check the origin in your Handshake func. So, if you want to accept
-// non-browser clients, which do not send an Origin header, set a
-// Server.Handshake that does not check the origin.
-type Handler func(*Conn)
-
-func checkOrigin(config *Config, req *http.Request) (err error) {
-	config.Origin, err = Origin(config, req)
-	if err == nil && config.Origin == nil {
-		return fmt.Errorf("null origin")
-	}
-	return err
-}
-
-// ServeHTTP implements the http.Handler interface for a WebSocket
-func (h Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	s := Server{Handler: h, Handshake: checkOrigin}
-	s.serveWebSocket(w, req)
-}
diff --git a/vendor/golang.org/x/net/websocket/websocket.go b/vendor/golang.org/x/net/websocket/websocket.go
deleted file mode 100644
index e242c89a..00000000
--- a/vendor/golang.org/x/net/websocket/websocket.go
+++ /dev/null
@@ -1,448 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package websocket implements a client and server for the WebSocket protocol
-// as specified in RFC 6455.
-//
-// This package currently lacks some features found in an alternative
-// and more actively maintained WebSocket package:
-//
-//     https://godoc.org/github.com/gorilla/websocket
-//
-package websocket // import "golang.org/x/net/websocket"
-
-import (
-	"bufio"
-	"crypto/tls"
-	"encoding/json"
-	"errors"
-	"io"
-	"io/ioutil"
-	"net"
-	"net/http"
-	"net/url"
-	"sync"
-	"time"
-)
-
-const (
-	ProtocolVersionHybi13    = 13
-	ProtocolVersionHybi      = ProtocolVersionHybi13
-	SupportedProtocolVersion = "13"
-
-	ContinuationFrame = 0
-	TextFrame         = 1
-	BinaryFrame       = 2
-	CloseFrame        = 8
-	PingFrame         = 9
-	PongFrame         = 10
-	UnknownFrame      = 255
-
-	DefaultMaxPayloadBytes = 32 << 20 // 32MB
-)
-
-// ProtocolError represents WebSocket protocol errors.
-type ProtocolError struct {
-	ErrorString string
-}
-
-func (err *ProtocolError) Error() string { return err.ErrorString }
-
-var (
-	ErrBadProtocolVersion   = &ProtocolError{"bad protocol version"}
-	ErrBadScheme            = &ProtocolError{"bad scheme"}
-	ErrBadStatus            = &ProtocolError{"bad status"}
-	ErrBadUpgrade           = &ProtocolError{"missing or bad upgrade"}
-	ErrBadWebSocketOrigin   = &ProtocolError{"missing or bad WebSocket-Origin"}
-	ErrBadWebSocketLocation = &ProtocolError{"missing or bad WebSocket-Location"}
-	ErrBadWebSocketProtocol = &ProtocolError{"missing or bad WebSocket-Protocol"}
-	ErrBadWebSocketVersion  = &ProtocolError{"missing or bad WebSocket Version"}
-	ErrChallengeResponse    = &ProtocolError{"mismatch challenge/response"}
-	ErrBadFrame             = &ProtocolError{"bad frame"}
-	ErrBadFrameBoundary     = &ProtocolError{"not on frame boundary"}
-	ErrNotWebSocket         = &ProtocolError{"not websocket protocol"}
-	ErrBadRequestMethod     = &ProtocolError{"bad method"}
-	ErrNotSupported         = &ProtocolError{"not supported"}
-)
-
-// ErrFrameTooLarge is returned by Codec's Receive method if payload size
-// exceeds limit set by Conn.MaxPayloadBytes
-var ErrFrameTooLarge = errors.New("websocket: frame payload size exceeds limit")
-
-// Addr is an implementation of net.Addr for WebSocket.
-type Addr struct {
-	*url.URL
-}
-
-// Network returns the network type for a WebSocket, "websocket".
-func (addr *Addr) Network() string { return "websocket" }
-
-// Config is a WebSocket configuration
-type Config struct {
-	// A WebSocket server address.
-	Location *url.URL
-
-	// A Websocket client origin.
-	Origin *url.URL
-
-	// WebSocket subprotocols.
-	Protocol []string
-
-	// WebSocket protocol version.
-	Version int
-
-	// TLS config for secure WebSocket (wss).
-	TlsConfig *tls.Config
-
-	// Additional header fields to be sent in WebSocket opening handshake.
-	Header http.Header
-
-	// Dialer used when opening websocket connections.
-	Dialer *net.Dialer
-
-	handshakeData map[string]string
-}
-
-// serverHandshaker is an interface to handle WebSocket server side handshake.
-type serverHandshaker interface {
-	// ReadHandshake reads handshake request message from client.
-	// Returns http response code and error if any.
-	ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error)
-
-	// AcceptHandshake accepts the client handshake request and sends
-	// handshake response back to client.
-	AcceptHandshake(buf *bufio.Writer) (err error)
-
-	// NewServerConn creates a new WebSocket connection.
-	NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) (conn *Conn)
-}
-
-// frameReader is an interface to read a WebSocket frame.
-type frameReader interface {
-	// Reader is to read payload of the frame.
-	io.Reader
-
-	// PayloadType returns payload type.
-	PayloadType() byte
-
-	// HeaderReader returns a reader to read header of the frame.
-	HeaderReader() io.Reader
-
-	// TrailerReader returns a reader to read trailer of the frame.
-	// If it returns nil, there is no trailer in the frame.
-	TrailerReader() io.Reader
-
-	// Len returns total length of the frame, including header and trailer.
-	Len() int
-}
-
-// frameReaderFactory is an interface to creates new frame reader.
-type frameReaderFactory interface {
-	NewFrameReader() (r frameReader, err error)
-}
-
-// frameWriter is an interface to write a WebSocket frame.
-type frameWriter interface {
-	// Writer is to write payload of the frame.
-	io.WriteCloser
-}
-
-// frameWriterFactory is an interface to create new frame writer.
-type frameWriterFactory interface {
-	NewFrameWriter(payloadType byte) (w frameWriter, err error)
-}
-
-type frameHandler interface {
-	HandleFrame(frame frameReader) (r frameReader, err error)
-	WriteClose(status int) (err error)
-}
-
-// Conn represents a WebSocket connection.
-//
-// Multiple goroutines may invoke methods on a Conn simultaneously.
-type Conn struct {
-	config  *Config
-	request *http.Request
-
-	buf *bufio.ReadWriter
-	rwc io.ReadWriteCloser
-
-	rio sync.Mutex
-	frameReaderFactory
-	frameReader
-
-	wio sync.Mutex
-	frameWriterFactory
-
-	frameHandler
-	PayloadType        byte
-	defaultCloseStatus int
-
-	// MaxPayloadBytes limits the size of frame payload received over Conn
-	// by Codec's Receive method. If zero, DefaultMaxPayloadBytes is used.
-	MaxPayloadBytes int
-}
-
-// Read implements the io.Reader interface:
-// it reads data of a frame from the WebSocket connection.
-// if msg is not large enough for the frame data, it fills the msg and next Read
-// will read the rest of the frame data.
-// it reads Text frame or Binary frame.
-func (ws *Conn) Read(msg []byte) (n int, err error) {
-	ws.rio.Lock()
-	defer ws.rio.Unlock()
-again:
-	if ws.frameReader == nil {
-		frame, err := ws.frameReaderFactory.NewFrameReader()
-		if err != nil {
-			return 0, err
-		}
-		ws.frameReader, err = ws.frameHandler.HandleFrame(frame)
-		if err != nil {
-			return 0, err
-		}
-		if ws.frameReader == nil {
-			goto again
-		}
-	}
-	n, err = ws.frameReader.Read(msg)
-	if err == io.EOF {
-		if trailer := ws.frameReader.TrailerReader(); trailer != nil {
-			io.Copy(ioutil.Discard, trailer)
-		}
-		ws.frameReader = nil
-		goto again
-	}
-	return n, err
-}
-
-// Write implements the io.Writer interface:
-// it writes data as a frame to the WebSocket connection.
-func (ws *Conn) Write(msg []byte) (n int, err error) {
-	ws.wio.Lock()
-	defer ws.wio.Unlock()
-	w, err := ws.frameWriterFactory.NewFrameWriter(ws.PayloadType)
-	if err != nil {
-		return 0, err
-	}
-	n, err = w.Write(msg)
-	w.Close()
-	return n, err
-}
-
-// Close implements the io.Closer interface.
-func (ws *Conn) Close() error {
-	err := ws.frameHandler.WriteClose(ws.defaultCloseStatus)
-	err1 := ws.rwc.Close()
-	if err != nil {
-		return err
-	}
-	return err1
-}
-
-func (ws *Conn) IsClientConn() bool { return ws.request == nil }
-func (ws *Conn) IsServerConn() bool { return ws.request != nil }
-
-// LocalAddr returns the WebSocket Origin for the connection for client, or
-// the WebSocket location for server.
-func (ws *Conn) LocalAddr() net.Addr {
-	if ws.IsClientConn() {
-		return &Addr{ws.config.Origin}
-	}
-	return &Addr{ws.config.Location}
-}
-
-// RemoteAddr returns the WebSocket location for the connection for client, or
-// the Websocket Origin for server.
-func (ws *Conn) RemoteAddr() net.Addr {
-	if ws.IsClientConn() {
-		return &Addr{ws.config.Location}
-	}
-	return &Addr{ws.config.Origin}
-}
-
-var errSetDeadline = errors.New("websocket: cannot set deadline: not using a net.Conn")
-
-// SetDeadline sets the connection's network read & write deadlines.
-func (ws *Conn) SetDeadline(t time.Time) error {
-	if conn, ok := ws.rwc.(net.Conn); ok {
-		return conn.SetDeadline(t)
-	}
-	return errSetDeadline
-}
-
-// SetReadDeadline sets the connection's network read deadline.
-func (ws *Conn) SetReadDeadline(t time.Time) error {
-	if conn, ok := ws.rwc.(net.Conn); ok {
-		return conn.SetReadDeadline(t)
-	}
-	return errSetDeadline
-}
-
-// SetWriteDeadline sets the connection's network write deadline.
-func (ws *Conn) SetWriteDeadline(t time.Time) error {
-	if conn, ok := ws.rwc.(net.Conn); ok {
-		return conn.SetWriteDeadline(t)
-	}
-	return errSetDeadline
-}
-
-// Config returns the WebSocket config.
-func (ws *Conn) Config() *Config { return ws.config }
-
-// Request returns the http request upgraded to the WebSocket.
-// It is nil for client side.
-func (ws *Conn) Request() *http.Request { return ws.request }
-
-// Codec represents a symmetric pair of functions that implement a codec.
-type Codec struct {
-	Marshal   func(v interface{}) (data []byte, payloadType byte, err error)
-	Unmarshal func(data []byte, payloadType byte, v interface{}) (err error)
-}
-
-// Send sends v marshaled by cd.Marshal as single frame to ws.
-func (cd Codec) Send(ws *Conn, v interface{}) (err error) {
-	data, payloadType, err := cd.Marshal(v)
-	if err != nil {
-		return err
-	}
-	ws.wio.Lock()
-	defer ws.wio.Unlock()
-	w, err := ws.frameWriterFactory.NewFrameWriter(payloadType)
-	if err != nil {
-		return err
-	}
-	_, err = w.Write(data)
-	w.Close()
-	return err
-}
-
-// Receive receives single frame from ws, unmarshaled by cd.Unmarshal and stores
-// in v. The whole frame payload is read to an in-memory buffer; max size of
-// payload is defined by ws.MaxPayloadBytes. If frame payload size exceeds
-// limit, ErrFrameTooLarge is returned; in this case frame is not read off wire
-// completely. The next call to Receive would read and discard leftover data of
-// previous oversized frame before processing next frame.
-func (cd Codec) Receive(ws *Conn, v interface{}) (err error) {
-	ws.rio.Lock()
-	defer ws.rio.Unlock()
-	if ws.frameReader != nil {
-		_, err = io.Copy(ioutil.Discard, ws.frameReader)
-		if err != nil {
-			return err
-		}
-		ws.frameReader = nil
-	}
-again:
-	frame, err := ws.frameReaderFactory.NewFrameReader()
-	if err != nil {
-		return err
-	}
-	frame, err = ws.frameHandler.HandleFrame(frame)
-	if err != nil {
-		return err
-	}
-	if frame == nil {
-		goto again
-	}
-	maxPayloadBytes := ws.MaxPayloadBytes
-	if maxPayloadBytes == 0 {
-		maxPayloadBytes = DefaultMaxPayloadBytes
-	}
-	if hf, ok := frame.(*hybiFrameReader); ok && hf.header.Length > int64(maxPayloadBytes) {
-		// payload size exceeds limit, no need to call Unmarshal
-		//
-		// set frameReader to current oversized frame so that
-		// the next call to this function can drain leftover
-		// data before processing the next frame
-		ws.frameReader = frame
-		return ErrFrameTooLarge
-	}
-	payloadType := frame.PayloadType()
-	data, err := ioutil.ReadAll(frame)
-	if err != nil {
-		return err
-	}
-	return cd.Unmarshal(data, payloadType, v)
-}
-
-func marshal(v interface{}) (msg []byte, payloadType byte, err error) {
-	switch data := v.(type) {
-	case string:
-		return []byte(data), TextFrame, nil
-	case []byte:
-		return data, BinaryFrame, nil
-	}
-	return nil, UnknownFrame, ErrNotSupported
-}
-
-func unmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
-	switch data := v.(type) {
-	case *string:
-		*data = string(msg)
-		return nil
-	case *[]byte:
-		*data = msg
-		return nil
-	}
-	return ErrNotSupported
-}
-
-/*
-Message is a codec to send/receive text/binary data in a frame on WebSocket connection.
-To send/receive text frame, use string type.
-To send/receive binary frame, use []byte type.
-
-Trivial usage:
-
-	import "websocket"
-
-	// receive text frame
-	var message string
-	websocket.Message.Receive(ws, &message)
-
-	// send text frame
-	message = "hello"
-	websocket.Message.Send(ws, message)
-
-	// receive binary frame
-	var data []byte
-	websocket.Message.Receive(ws, &data)
-
-	// send binary frame
-	data = []byte{0, 1, 2}
-	websocket.Message.Send(ws, data)
-
-*/
-var Message = Codec{marshal, unmarshal}
-
-func jsonMarshal(v interface{}) (msg []byte, payloadType byte, err error) {
-	msg, err = json.Marshal(v)
-	return msg, TextFrame, err
-}
-
-func jsonUnmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
-	return json.Unmarshal(msg, v)
-}
-
-/*
-JSON is a codec to send/receive JSON data in a frame from a WebSocket connection.
-
-Trivial usage:
-
-	import "websocket"
-
-	type T struct {
-		Msg string
-		Count int
-	}
-
-	// receive JSON type T
-	var data T
-	websocket.JSON.Receive(ws, &data)
-
-	// send JSON type T
-	websocket.JSON.Send(ws, data)
-*/
-var JSON = Codec{jsonMarshal, jsonUnmarshal}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 24b5d456..3748db19 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -95,7 +95,7 @@ github.com/nicksnyder/go-i18n/i18n
 github.com/nicksnyder/go-i18n/i18n/bundle
 github.com/nicksnyder/go-i18n/i18n/language
 github.com/nicksnyder/go-i18n/i18n/translation
-# github.com/nlopes/slack v0.0.0-20180101221843-107290b5bbaf
+# github.com/nlopes/slack v0.3.1-0.20180805133408-21749ab136a8
 github.com/nlopes/slack
 # github.com/paulrosania/go-charset v0.0.0-20151028000031-621bb39fcc83
 github.com/paulrosania/go-charset/charset
@@ -106,6 +106,8 @@ github.com/pborman/uuid
 github.com/pelletier/go-toml
 # github.com/peterhellberg/emojilib v0.0.0-20170616163716-41920917e271
 github.com/peterhellberg/emojilib
+# github.com/pkg/errors v0.8.0
+github.com/pkg/errors
 # github.com/pmezard/go-difflib v1.0.0
 github.com/pmezard/go-difflib/difflib
 # github.com/rs/xid v0.0.0-20180525034800-088c5cf1423a
@@ -155,8 +157,6 @@ golang.org/x/crypto/ed25519
 golang.org/x/crypto/internal/chacha20
 golang.org/x/crypto/blowfish
 golang.org/x/crypto/ed25519/internal/edwards25519
-# golang.org/x/net v0.0.0-20180108090419-434ec0c7fe37
-golang.org/x/net/websocket
 # golang.org/x/sys v0.0.0-20171130163741-8b4580aae2a0
 golang.org/x/sys/unix
 golang.org/x/sys/windows