Use mattermost v5 module (#1192)

9 files changed, 1169 insertions, 0 deletions

diff --git a/vendor/github.com/blang/semver/.travis.yml b/vendor/github.com/blang/semver/.travis.yml
new file mode 100644
index 00000000..102fb9a6
--- /dev/null
+++ b/vendor/github.com/blang/semver/.travis.yml
@@ -0,0 +1,21 @@
+language: go
+matrix:
+  include:
+  - go: 1.4.3
+  - go: 1.5.4
+  - go: 1.6.3
+  - go: 1.7
+  - go: tip
+  allow_failures:
+  - go: tip
+install:
+- go get golang.org/x/tools/cmd/cover
+- go get github.com/mattn/goveralls
+script:
+- echo "Test and track coverage" ; $HOME/gopath/bin/goveralls -package "." -service=travis-ci
+  -repotoken $COVERALLS_TOKEN
+- echo "Build examples" ; cd examples && go build
+- echo "Check if gofmt'd" ; diff -u <(echo -n) <(gofmt -d -s .)
+env:
+  global:
+    secure: HroGEAUQpVq9zX1b1VIkraLiywhGbzvNnTZq2TMxgK7JHP8xqNplAeF1izrR2i4QLL9nsY+9WtYss4QuPvEtZcVHUobw6XnL6radF7jS1LgfYZ9Y7oF+zogZ2I5QUMRLGA7rcxQ05s7mKq3XZQfeqaNts4bms/eZRefWuaFZbkw=
diff --git a/vendor/github.com/blang/semver/LICENSE b/vendor/github.com/blang/semver/LICENSE
new file mode 100644
index 00000000..5ba5c86f
--- /dev/null
+++ b/vendor/github.com/blang/semver/LICENSE
@@ -0,0 +1,22 @@
+The MIT License
+
+Copyright (c) 2014 Benedikt Lang <github at benediktlang.de>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
diff --git a/vendor/github.com/blang/semver/README.md b/vendor/github.com/blang/semver/README.md
new file mode 100644
index 00000000..08b2e4a3
--- /dev/null
+++ b/vendor/github.com/blang/semver/README.md
@@ -0,0 +1,194 @@
+semver for golang [![Build Status](https://travis-ci.org/blang/semver.svg?branch=master)](https://travis-ci.org/blang/semver) [![GoDoc](https://godoc.org/github.com/blang/semver?status.png)](https://godoc.org/github.com/blang/semver) [![Coverage Status](https://img.shields.io/coveralls/blang/semver.svg)](https://coveralls.io/r/blang/semver?branch=master)
+======
+
+semver is a [Semantic Versioning](http://semver.org/) library written in golang. It fully covers spec version `2.0.0`.
+
+Usage
+-----
+```bash
+$ go get github.com/blang/semver
+```
+Note: Always vendor your dependencies or fix on a specific version tag.
+
+```go
+import github.com/blang/semver
+v1, err := semver.Make("1.0.0-beta")
+v2, err := semver.Make("2.0.0-beta")
+v1.Compare(v2)
+```
+
+Also check the [GoDocs](http://godoc.org/github.com/blang/semver).
+
+Why should I use this lib?
+-----
+
+- Fully spec compatible
+- No reflection
+- No regex
+- Fully tested (Coverage >99%)
+- Readable parsing/validation errors
+- Fast (See [Benchmarks](#benchmarks))
+- Only Stdlib
+- Uses values instead of pointers
+- Many features, see below
+
+
+Features
+-----
+
+- Parsing and validation at all levels
+- Comparator-like comparisons
+- Compare Helper Methods
+- InPlace manipulation
+- Ranges `>=1.0.0 <2.0.0 || >=3.0.0 !3.0.1-beta.1`
+- Wildcards `>=1.x`, `<=2.5.x`
+- Sortable (implements sort.Interface)
+- database/sql compatible (sql.Scanner/Valuer)
+- encoding/json compatible (json.Marshaler/Unmarshaler)
+
+Ranges
+------
+
+A `Range` is a set of conditions which specify which versions satisfy the range.
+
+A condition is composed of an operator and a version. The supported operators are:
+
+- `<1.0.0` Less than `1.0.0`
+- `<=1.0.0` Less than or equal to `1.0.0`
+- `>1.0.0` Greater than `1.0.0`
+- `>=1.0.0` Greater than or equal to `1.0.0`
+- `1.0.0`, `=1.0.0`, `==1.0.0` Equal to `1.0.0`
+- `!1.0.0`, `!=1.0.0` Not equal to `1.0.0`. Excludes version `1.0.0`.
+
+Note that spaces between the operator and the version will be gracefully tolerated.
+
+A `Range` can link multiple `Ranges` separated by space:
+
+Ranges can be linked by logical AND:
+
+  - `>1.0.0 <2.0.0` would match between both ranges, so `1.1.1` and `1.8.7` but not `1.0.0` or `2.0.0`
+  - `>1.0.0 <3.0.0 !2.0.3-beta.2` would match every version between `1.0.0` and `3.0.0` except `2.0.3-beta.2`
+
+Ranges can also be linked by logical OR:
+
+  - `<2.0.0 || >=3.0.0` would match `1.x.x` and `3.x.x` but not `2.x.x`
+
+AND has a higher precedence than OR. It's not possible to use brackets.
+
+Ranges can be combined by both AND and OR
+
+  - `>1.0.0 <2.0.0 || >3.0.0 !4.2.1` would match `1.2.3`, `1.9.9`, `3.1.1`, but not `4.2.1`, `2.1.1`
+
+Range usage:
+
+```
+v, err := semver.Parse("1.2.3")
+range, err := semver.ParseRange(">1.0.0 <2.0.0 || >=3.0.0")
+if range(v) {
+    //valid
+}
+
+```
+
+Example
+-----
+
+Have a look at full examples in [examples/main.go](examples/main.go)
+
+```go
+import github.com/blang/semver
+
+v, err := semver.Make("0.0.1-alpha.preview+123.github")
+fmt.Printf("Major: %d\n", v.Major)
+fmt.Printf("Minor: %d\n", v.Minor)
+fmt.Printf("Patch: %d\n", v.Patch)
+fmt.Printf("Pre: %s\n", v.Pre)
+fmt.Printf("Build: %s\n", v.Build)
+
+// Prerelease versions array
+if len(v.Pre) > 0 {
+    fmt.Println("Prerelease versions:")
+    for i, pre := range v.Pre {
+        fmt.Printf("%d: %q\n", i, pre)
+    }
+}
+
+// Build meta data array
+if len(v.Build) > 0 {
+    fmt.Println("Build meta data:")
+    for i, build := range v.Build {
+        fmt.Printf("%d: %q\n", i, build)
+    }
+}
+
+v001, err := semver.Make("0.0.1")
+// Compare using helpers: v.GT(v2), v.LT, v.GTE, v.LTE
+v001.GT(v) == true
+v.LT(v001) == true
+v.GTE(v) == true
+v.LTE(v) == true
+
+// Or use v.Compare(v2) for comparisons (-1, 0, 1):
+v001.Compare(v) == 1
+v.Compare(v001) == -1
+v.Compare(v) == 0
+
+// Manipulate Version in place:
+v.Pre[0], err = semver.NewPRVersion("beta")
+if err != nil {
+    fmt.Printf("Error parsing pre release version: %q", err)
+}
+
+fmt.Println("\nValidate versions:")
+v.Build[0] = "?"
+
+err = v.Validate()
+if err != nil {
+    fmt.Printf("Validation failed: %s\n", err)
+}
+```
+
+
+Benchmarks
+-----
+
+    BenchmarkParseSimple-4           5000000    390    ns/op    48 B/op   1 allocs/op
+    BenchmarkParseComplex-4          1000000   1813    ns/op   256 B/op   7 allocs/op
+    BenchmarkParseAverage-4          1000000   1171    ns/op   163 B/op   4 allocs/op
+    BenchmarkStringSimple-4         20000000    119    ns/op    16 B/op   1 allocs/op
+    BenchmarkStringLarger-4         10000000    206    ns/op    32 B/op   2 allocs/op
+    BenchmarkStringComplex-4         5000000    324    ns/op    80 B/op   3 allocs/op
+    BenchmarkStringAverage-4         5000000    273    ns/op    53 B/op   2 allocs/op
+    BenchmarkValidateSimple-4      200000000      9.33 ns/op     0 B/op   0 allocs/op
+    BenchmarkValidateComplex-4       3000000    469    ns/op     0 B/op   0 allocs/op
+    BenchmarkValidateAverage-4       5000000    256    ns/op     0 B/op   0 allocs/op
+    BenchmarkCompareSimple-4       100000000     11.8  ns/op     0 B/op   0 allocs/op
+    BenchmarkCompareComplex-4       50000000     30.8  ns/op     0 B/op   0 allocs/op
+    BenchmarkCompareAverage-4       30000000     41.5  ns/op     0 B/op   0 allocs/op
+    BenchmarkSort-4                  3000000    419    ns/op   256 B/op   2 allocs/op
+    BenchmarkRangeParseSimple-4      2000000    850    ns/op   192 B/op   5 allocs/op
+    BenchmarkRangeParseAverage-4     1000000   1677    ns/op   400 B/op  10 allocs/op
+    BenchmarkRangeParseComplex-4      300000   5214    ns/op  1440 B/op  30 allocs/op
+    BenchmarkRangeMatchSimple-4     50000000     25.6  ns/op     0 B/op   0 allocs/op
+    BenchmarkRangeMatchAverage-4    30000000     56.4  ns/op     0 B/op   0 allocs/op
+    BenchmarkRangeMatchComplex-4    10000000    153    ns/op     0 B/op   0 allocs/op
+
+See benchmark cases at [semver_test.go](semver_test.go)
+
+
+Motivation
+-----
+
+I simply couldn't find any lib supporting the full spec. Others were just wrong or used reflection and regex which i don't like.
+
+
+Contribution
+-----
+
+Feel free to make a pull request. For bigger changes create a issue first to discuss about it.
+
+
+License
+-----
+
+See [LICENSE](LICENSE) file.
diff --git a/vendor/github.com/blang/semver/json.go b/vendor/github.com/blang/semver/json.go
new file mode 100644
index 00000000..a74bf7c4
--- /dev/null
+++ b/vendor/github.com/blang/semver/json.go
@@ -0,0 +1,23 @@
+package semver
+
+import (
+	"encoding/json"
+)
+
+// MarshalJSON implements the encoding/json.Marshaler interface.
+func (v Version) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.String())
+}
+
+// UnmarshalJSON implements the encoding/json.Unmarshaler interface.
+func (v *Version) UnmarshalJSON(data []byte) (err error) {
+	var versionString string
+
+	if err = json.Unmarshal(data, &versionString); err != nil {
+		return
+	}
+
+	*v, err = Parse(versionString)
+
+	return
+}
diff --git a/vendor/github.com/blang/semver/package.json b/vendor/github.com/blang/semver/package.json
new file mode 100644
index 00000000..1cf8ebdd
--- /dev/null
+++ b/vendor/github.com/blang/semver/package.json
@@ -0,0 +1,17 @@
+{
+  "author": "blang",
+  "bugs": {
+    "URL": "https://github.com/blang/semver/issues",
+    "url": "https://github.com/blang/semver/issues"
+  },
+  "gx": {
+    "dvcsimport": "github.com/blang/semver"
+  },
+  "gxVersion": "0.10.0",
+  "language": "go",
+  "license": "MIT",
+  "name": "semver",
+  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
+  "version": "3.5.1"
+}
+
diff --git a/vendor/github.com/blang/semver/range.go b/vendor/github.com/blang/semver/range.go
new file mode 100644
index 00000000..fca406d4
--- /dev/null
+++ b/vendor/github.com/blang/semver/range.go
@@ -0,0 +1,416 @@
+package semver
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode"
+)
+
+type wildcardType int
+
+const (
+	noneWildcard  wildcardType = iota
+	majorWildcard wildcardType = 1
+	minorWildcard wildcardType = 2
+	patchWildcard wildcardType = 3
+)
+
+func wildcardTypefromInt(i int) wildcardType {
+	switch i {
+	case 1:
+		return majorWildcard
+	case 2:
+		return minorWildcard
+	case 3:
+		return patchWildcard
+	default:
+		return noneWildcard
+	}
+}
+
+type comparator func(Version, Version) bool
+
+var (
+	compEQ comparator = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) == 0
+	}
+	compNE = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) != 0
+	}
+	compGT = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) == 1
+	}
+	compGE = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) >= 0
+	}
+	compLT = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) == -1
+	}
+	compLE = func(v1 Version, v2 Version) bool {
+		return v1.Compare(v2) <= 0
+	}
+)
+
+type versionRange struct {
+	v Version
+	c comparator
+}
+
+// rangeFunc creates a Range from the given versionRange.
+func (vr *versionRange) rangeFunc() Range {
+	return Range(func(v Version) bool {
+		return vr.c(v, vr.v)
+	})
+}
+
+// Range represents a range of versions.
+// A Range can be used to check if a Version satisfies it:
+//
+//     range, err := semver.ParseRange(">1.0.0 <2.0.0")
+//     range(semver.MustParse("1.1.1") // returns true
+type Range func(Version) bool
+
+// OR combines the existing Range with another Range using logical OR.
+func (rf Range) OR(f Range) Range {
+	return Range(func(v Version) bool {
+		return rf(v) || f(v)
+	})
+}
+
+// AND combines the existing Range with another Range using logical AND.
+func (rf Range) AND(f Range) Range {
+	return Range(func(v Version) bool {
+		return rf(v) && f(v)
+	})
+}
+
+// ParseRange parses a range and returns a Range.
+// If the range could not be parsed an error is returned.
+//
+// Valid ranges are:
+//   - "<1.0.0"
+//   - "<=1.0.0"
+//   - ">1.0.0"
+//   - ">=1.0.0"
+//   - "1.0.0", "=1.0.0", "==1.0.0"
+//   - "!1.0.0", "!=1.0.0"
+//
+// A Range can consist of multiple ranges separated by space:
+// Ranges can be linked by logical AND:
+//   - ">1.0.0 <2.0.0" would match between both ranges, so "1.1.1" and "1.8.7" but not "1.0.0" or "2.0.0"
+//   - ">1.0.0 <3.0.0 !2.0.3-beta.2" would match every version between 1.0.0 and 3.0.0 except 2.0.3-beta.2
+//
+// Ranges can also be linked by logical OR:
+//   - "<2.0.0 || >=3.0.0" would match "1.x.x" and "3.x.x" but not "2.x.x"
+//
+// AND has a higher precedence than OR. It's not possible to use brackets.
+//
+// Ranges can be combined by both AND and OR
+//
+//  - `>1.0.0 <2.0.0 || >3.0.0 !4.2.1` would match `1.2.3`, `1.9.9`, `3.1.1`, but not `4.2.1`, `2.1.1`
+func ParseRange(s string) (Range, error) {
+	parts := splitAndTrim(s)
+	orParts, err := splitORParts(parts)
+	if err != nil {
+		return nil, err
+	}
+	expandedParts, err := expandWildcardVersion(orParts)
+	if err != nil {
+		return nil, err
+	}
+	var orFn Range
+	for _, p := range expandedParts {
+		var andFn Range
+		for _, ap := range p {
+			opStr, vStr, err := splitComparatorVersion(ap)
+			if err != nil {
+				return nil, err
+			}
+			vr, err := buildVersionRange(opStr, vStr)
+			if err != nil {
+				return nil, fmt.Errorf("Could not parse Range %q: %s", ap, err)
+			}
+			rf := vr.rangeFunc()
+
+			// Set function
+			if andFn == nil {
+				andFn = rf
+			} else { // Combine with existing function
+				andFn = andFn.AND(rf)
+			}
+		}
+		if orFn == nil {
+			orFn = andFn
+		} else {
+			orFn = orFn.OR(andFn)
+		}
+
+	}
+	return orFn, nil
+}
+
+// splitORParts splits the already cleaned parts by '||'.
+// Checks for invalid positions of the operator and returns an
+// error if found.
+func splitORParts(parts []string) ([][]string, error) {
+	var ORparts [][]string
+	last := 0
+	for i, p := range parts {
+		if p == "||" {
+			if i == 0 {
+				return nil, fmt.Errorf("First element in range is '||'")
+			}
+			ORparts = append(ORparts, parts[last:i])
+			last = i + 1
+		}
+	}
+	if last == len(parts) {
+		return nil, fmt.Errorf("Last element in range is '||'")
+	}
+	ORparts = append(ORparts, parts[last:])
+	return ORparts, nil
+}
+
+// buildVersionRange takes a slice of 2: operator and version
+// and builds a versionRange, otherwise an error.
+func buildVersionRange(opStr, vStr string) (*versionRange, error) {
+	c := parseComparator(opStr)
+	if c == nil {
+		return nil, fmt.Errorf("Could not parse comparator %q in %q", opStr, strings.Join([]string{opStr, vStr}, ""))
+	}
+	v, err := Parse(vStr)
+	if err != nil {
+		return nil, fmt.Errorf("Could not parse version %q in %q: %s", vStr, strings.Join([]string{opStr, vStr}, ""), err)
+	}
+
+	return &versionRange{
+		v: v,
+		c: c,
+	}, nil
+
+}
+
+// inArray checks if a byte is contained in an array of bytes
+func inArray(s byte, list []byte) bool {
+	for _, el := range list {
+		if el == s {
+			return true
+		}
+	}
+	return false
+}
+
+// splitAndTrim splits a range string by spaces and cleans whitespaces
+func splitAndTrim(s string) (result []string) {
+	last := 0
+	var lastChar byte
+	excludeFromSplit := []byte{'>', '<', '='}
+	for i := 0; i < len(s); i++ {
+		if s[i] == ' ' && !inArray(lastChar, excludeFromSplit) {
+			if last < i-1 {
+				result = append(result, s[last:i])
+			}
+			last = i + 1
+		} else if s[i] != ' ' {
+			lastChar = s[i]
+		}
+	}
+	if last < len(s)-1 {
+		result = append(result, s[last:])
+	}
+
+	for i, v := range result {
+		result[i] = strings.Replace(v, " ", "", -1)
+	}
+
+	// parts := strings.Split(s, " ")
+	// for _, x := range parts {
+	// 	if s := strings.TrimSpace(x); len(s) != 0 {
+	// 		result = append(result, s)
+	// 	}
+	// }
+	return
+}
+
+// splitComparatorVersion splits the comparator from the version.
+// Input must be free of leading or trailing spaces.
+func splitComparatorVersion(s string) (string, string, error) {
+	i := strings.IndexFunc(s, unicode.IsDigit)
+	if i == -1 {
+		return "", "", fmt.Errorf("Could not get version from string: %q", s)
+	}
+	return strings.TrimSpace(s[0:i]), s[i:], nil
+}
+
+// getWildcardType will return the type of wildcard that the
+// passed version contains
+func getWildcardType(vStr string) wildcardType {
+	parts := strings.Split(vStr, ".")
+	nparts := len(parts)
+	wildcard := parts[nparts-1]
+
+	possibleWildcardType := wildcardTypefromInt(nparts)
+	if wildcard == "x" {
+		return possibleWildcardType
+	}
+
+	return noneWildcard
+}
+
+// createVersionFromWildcard will convert a wildcard version
+// into a regular version, replacing 'x's with '0's, handling
+// special cases like '1.x.x' and '1.x'
+func createVersionFromWildcard(vStr string) string {
+	// handle 1.x.x
+	vStr2 := strings.Replace(vStr, ".x.x", ".x", 1)
+	vStr2 = strings.Replace(vStr2, ".x", ".0", 1)
+	parts := strings.Split(vStr2, ".")
+
+	// handle 1.x
+	if len(parts) == 2 {
+		return vStr2 + ".0"
+	}
+
+	return vStr2
+}
+
+// incrementMajorVersion will increment the major version
+// of the passed version
+func incrementMajorVersion(vStr string) (string, error) {
+	parts := strings.Split(vStr, ".")
+	i, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return "", err
+	}
+	parts[0] = strconv.Itoa(i + 1)
+
+	return strings.Join(parts, "."), nil
+}
+
+// incrementMajorVersion will increment the minor version
+// of the passed version
+func incrementMinorVersion(vStr string) (string, error) {
+	parts := strings.Split(vStr, ".")
+	i, err := strconv.Atoi(parts[1])
+	if err != nil {
+		return "", err
+	}
+	parts[1] = strconv.Itoa(i + 1)
+
+	return strings.Join(parts, "."), nil
+}
+
+// expandWildcardVersion will expand wildcards inside versions
+// following these rules:
+//
+// * when dealing with patch wildcards:
+// >= 1.2.x    will become    >= 1.2.0
+// <= 1.2.x    will become    <  1.3.0
+// >  1.2.x    will become    >= 1.3.0
+// <  1.2.x    will become    <  1.2.0
+// != 1.2.x    will become    <  1.2.0 >= 1.3.0
+//
+// * when dealing with minor wildcards:
+// >= 1.x      will become    >= 1.0.0
+// <= 1.x      will become    <  2.0.0
+// >  1.x      will become    >= 2.0.0
+// <  1.0      will become    <  1.0.0
+// != 1.x      will become    <  1.0.0 >= 2.0.0
+//
+// * when dealing with wildcards without
+// version operator:
+// 1.2.x       will become    >= 1.2.0 < 1.3.0
+// 1.x         will become    >= 1.0.0 < 2.0.0
+func expandWildcardVersion(parts [][]string) ([][]string, error) {
+	var expandedParts [][]string
+	for _, p := range parts {
+		var newParts []string
+		for _, ap := range p {
+			if strings.Index(ap, "x") != -1 {
+				opStr, vStr, err := splitComparatorVersion(ap)
+				if err != nil {
+					return nil, err
+				}
+
+				versionWildcardType := getWildcardType(vStr)
+				flatVersion := createVersionFromWildcard(vStr)
+
+				var resultOperator string
+				var shouldIncrementVersion bool
+				switch opStr {
+				case ">":
+					resultOperator = ">="
+					shouldIncrementVersion = true
+				case ">=":
+					resultOperator = ">="
+				case "<":
+					resultOperator = "<"
+				case "<=":
+					resultOperator = "<"
+					shouldIncrementVersion = true
+				case "", "=", "==":
+					newParts = append(newParts, ">="+flatVersion)
+					resultOperator = "<"
+					shouldIncrementVersion = true
+				case "!=", "!":
+					newParts = append(newParts, "<"+flatVersion)
+					resultOperator = ">="
+					shouldIncrementVersion = true
+				}
+
+				var resultVersion string
+				if shouldIncrementVersion {
+					switch versionWildcardType {
+					case patchWildcard:
+						resultVersion, _ = incrementMinorVersion(flatVersion)
+					case minorWildcard:
+						resultVersion, _ = incrementMajorVersion(flatVersion)
+					}
+				} else {
+					resultVersion = flatVersion
+				}
+
+				ap = resultOperator + resultVersion
+			}
+			newParts = append(newParts, ap)
+		}
+		expandedParts = append(expandedParts, newParts)
+	}
+
+	return expandedParts, nil
+}
+
+func parseComparator(s string) comparator {
+	switch s {
+	case "==":
+		fallthrough
+	case "":
+		fallthrough
+	case "=":
+		return compEQ
+	case ">":
+		return compGT
+	case ">=":
+		return compGE
+	case "<":
+		return compLT
+	case "<=":
+		return compLE
+	case "!":
+		fallthrough
+	case "!=":
+		return compNE
+	}
+
+	return nil
+}
+
+// MustParseRange is like ParseRange but panics if the range cannot be parsed.
+func MustParseRange(s string) Range {
+	r, err := ParseRange(s)
+	if err != nil {
+		panic(`semver: ParseRange(` + s + `): ` + err.Error())
+	}
+	return r
+}
diff --git a/vendor/github.com/blang/semver/semver.go b/vendor/github.com/blang/semver/semver.go
new file mode 100644
index 00000000..8ee0842e
--- /dev/null
+++ b/vendor/github.com/blang/semver/semver.go
@@ -0,0 +1,418 @@
+package semver
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	numbers  string = "0123456789"
+	alphas          = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-"
+	alphanum        = alphas + numbers
+)
+
+// SpecVersion is the latest fully supported spec version of semver
+var SpecVersion = Version{
+	Major: 2,
+	Minor: 0,
+	Patch: 0,
+}
+
+// Version represents a semver compatible version
+type Version struct {
+	Major uint64
+	Minor uint64
+	Patch uint64
+	Pre   []PRVersion
+	Build []string //No Precendence
+}
+
+// Version to string
+func (v Version) String() string {
+	b := make([]byte, 0, 5)
+	b = strconv.AppendUint(b, v.Major, 10)
+	b = append(b, '.')
+	b = strconv.AppendUint(b, v.Minor, 10)
+	b = append(b, '.')
+	b = strconv.AppendUint(b, v.Patch, 10)
+
+	if len(v.Pre) > 0 {
+		b = append(b, '-')
+		b = append(b, v.Pre[0].String()...)
+
+		for _, pre := range v.Pre[1:] {
+			b = append(b, '.')
+			b = append(b, pre.String()...)
+		}
+	}
+
+	if len(v.Build) > 0 {
+		b = append(b, '+')
+		b = append(b, v.Build[0]...)
+
+		for _, build := range v.Build[1:] {
+			b = append(b, '.')
+			b = append(b, build...)
+		}
+	}
+
+	return string(b)
+}
+
+// Equals checks if v is equal to o.
+func (v Version) Equals(o Version) bool {
+	return (v.Compare(o) == 0)
+}
+
+// EQ checks if v is equal to o.
+func (v Version) EQ(o Version) bool {
+	return (v.Compare(o) == 0)
+}
+
+// NE checks if v is not equal to o.
+func (v Version) NE(o Version) bool {
+	return (v.Compare(o) != 0)
+}
+
+// GT checks if v is greater than o.
+func (v Version) GT(o Version) bool {
+	return (v.Compare(o) == 1)
+}
+
+// GTE checks if v is greater than or equal to o.
+func (v Version) GTE(o Version) bool {
+	return (v.Compare(o) >= 0)
+}
+
+// GE checks if v is greater than or equal to o.
+func (v Version) GE(o Version) bool {
+	return (v.Compare(o) >= 0)
+}
+
+// LT checks if v is less than o.
+func (v Version) LT(o Version) bool {
+	return (v.Compare(o) == -1)
+}
+
+// LTE checks if v is less than or equal to o.
+func (v Version) LTE(o Version) bool {
+	return (v.Compare(o) <= 0)
+}
+
+// LE checks if v is less than or equal to o.
+func (v Version) LE(o Version) bool {
+	return (v.Compare(o) <= 0)
+}
+
+// Compare compares Versions v to o:
+// -1 == v is less than o
+// 0 == v is equal to o
+// 1 == v is greater than o
+func (v Version) Compare(o Version) int {
+	if v.Major != o.Major {
+		if v.Major > o.Major {
+			return 1
+		}
+		return -1
+	}
+	if v.Minor != o.Minor {
+		if v.Minor > o.Minor {
+			return 1
+		}
+		return -1
+	}
+	if v.Patch != o.Patch {
+		if v.Patch > o.Patch {
+			return 1
+		}
+		return -1
+	}
+
+	// Quick comparison if a version has no prerelease versions
+	if len(v.Pre) == 0 && len(o.Pre) == 0 {
+		return 0
+	} else if len(v.Pre) == 0 && len(o.Pre) > 0 {
+		return 1
+	} else if len(v.Pre) > 0 && len(o.Pre) == 0 {
+		return -1
+	}
+
+	i := 0
+	for ; i < len(v.Pre) && i < len(o.Pre); i++ {
+		if comp := v.Pre[i].Compare(o.Pre[i]); comp == 0 {
+			continue
+		} else if comp == 1 {
+			return 1
+		} else {
+			return -1
+		}
+	}
+
+	// If all pr versions are the equal but one has further prversion, this one greater
+	if i == len(v.Pre) && i == len(o.Pre) {
+		return 0
+	} else if i == len(v.Pre) && i < len(o.Pre) {
+		return -1
+	} else {
+		return 1
+	}
+
+}
+
+// Validate validates v and returns error in case
+func (v Version) Validate() error {
+	// Major, Minor, Patch already validated using uint64
+
+	for _, pre := range v.Pre {
+		if !pre.IsNum { //Numeric prerelease versions already uint64
+			if len(pre.VersionStr) == 0 {
+				return fmt.Errorf("Prerelease can not be empty %q", pre.VersionStr)
+			}
+			if !containsOnly(pre.VersionStr, alphanum) {
+				return fmt.Errorf("Invalid character(s) found in prerelease %q", pre.VersionStr)
+			}
+		}
+	}
+
+	for _, build := range v.Build {
+		if len(build) == 0 {
+			return fmt.Errorf("Build meta data can not be empty %q", build)
+		}
+		if !containsOnly(build, alphanum) {
+			return fmt.Errorf("Invalid character(s) found in build meta data %q", build)
+		}
+	}
+
+	return nil
+}
+
+// New is an alias for Parse and returns a pointer, parses version string and returns a validated Version or error
+func New(s string) (vp *Version, err error) {
+	v, err := Parse(s)
+	vp = &v
+	return
+}
+
+// Make is an alias for Parse, parses version string and returns a validated Version or error
+func Make(s string) (Version, error) {
+	return Parse(s)
+}
+
+// ParseTolerant allows for certain version specifications that do not strictly adhere to semver
+// specs to be parsed by this library. It does so by normalizing versions before passing them to
+// Parse(). It currently trims spaces, removes a "v" prefix, and adds a 0 patch number to versions
+// with only major and minor components specified
+func ParseTolerant(s string) (Version, error) {
+	s = strings.TrimSpace(s)
+	s = strings.TrimPrefix(s, "v")
+
+	// Split into major.minor.(patch+pr+meta)
+	parts := strings.SplitN(s, ".", 3)
+	if len(parts) < 3 {
+		if strings.ContainsAny(parts[len(parts)-1], "+-") {
+			return Version{}, errors.New("Short version cannot contain PreRelease/Build meta data")
+		}
+		for len(parts) < 3 {
+			parts = append(parts, "0")
+		}
+		s = strings.Join(parts, ".")
+	}
+
+	return Parse(s)
+}
+
+// Parse parses version string and returns a validated Version or error
+func Parse(s string) (Version, error) {
+	if len(s) == 0 {
+		return Version{}, errors.New("Version string empty")
+	}
+
+	// Split into major.minor.(patch+pr+meta)
+	parts := strings.SplitN(s, ".", 3)
+	if len(parts) != 3 {
+		return Version{}, errors.New("No Major.Minor.Patch elements found")
+	}
+
+	// Major
+	if !containsOnly(parts[0], numbers) {
+		return Version{}, fmt.Errorf("Invalid character(s) found in major number %q", parts[0])
+	}
+	if hasLeadingZeroes(parts[0]) {
+		return Version{}, fmt.Errorf("Major number must not contain leading zeroes %q", parts[0])
+	}
+	major, err := strconv.ParseUint(parts[0], 10, 64)
+	if err != nil {
+		return Version{}, err
+	}
+
+	// Minor
+	if !containsOnly(parts[1], numbers) {
+		return Version{}, fmt.Errorf("Invalid character(s) found in minor number %q", parts[1])
+	}
+	if hasLeadingZeroes(parts[1]) {
+		return Version{}, fmt.Errorf("Minor number must not contain leading zeroes %q", parts[1])
+	}
+	minor, err := strconv.ParseUint(parts[1], 10, 64)
+	if err != nil {
+		return Version{}, err
+	}
+
+	v := Version{}
+	v.Major = major
+	v.Minor = minor
+
+	var build, prerelease []string
+	patchStr := parts[2]
+
+	if buildIndex := strings.IndexRune(patchStr, '+'); buildIndex != -1 {
+		build = strings.Split(patchStr[buildIndex+1:], ".")
+		patchStr = patchStr[:buildIndex]
+	}
+
+	if preIndex := strings.IndexRune(patchStr, '-'); preIndex != -1 {
+		prerelease = strings.Split(patchStr[preIndex+1:], ".")
+		patchStr = patchStr[:preIndex]
+	}
+
+	if !containsOnly(patchStr, numbers) {
+		return Version{}, fmt.Errorf("Invalid character(s) found in patch number %q", patchStr)
+	}
+	if hasLeadingZeroes(patchStr) {
+		return Version{}, fmt.Errorf("Patch number must not contain leading zeroes %q", patchStr)
+	}
+	patch, err := strconv.ParseUint(patchStr, 10, 64)
+	if err != nil {
+		return Version{}, err
+	}
+
+	v.Patch = patch
+
+	// Prerelease
+	for _, prstr := range prerelease {
+		parsedPR, err := NewPRVersion(prstr)
+		if err != nil {
+			return Version{}, err
+		}
+		v.Pre = append(v.Pre, parsedPR)
+	}
+
+	// Build meta data
+	for _, str := range build {
+		if len(str) == 0 {
+			return Version{}, errors.New("Build meta data is empty")
+		}
+		if !containsOnly(str, alphanum) {
+			return Version{}, fmt.Errorf("Invalid character(s) found in build meta data %q", str)
+		}
+		v.Build = append(v.Build, str)
+	}
+
+	return v, nil
+}
+
+// MustParse is like Parse but panics if the version cannot be parsed.
+func MustParse(s string) Version {
+	v, err := Parse(s)
+	if err != nil {
+		panic(`semver: Parse(` + s + `): ` + err.Error())
+	}
+	return v
+}
+
+// PRVersion represents a PreRelease Version
+type PRVersion struct {
+	VersionStr string
+	VersionNum uint64
+	IsNum      bool
+}
+
+// NewPRVersion creates a new valid prerelease version
+func NewPRVersion(s string) (PRVersion, error) {
+	if len(s) == 0 {
+		return PRVersion{}, errors.New("Prerelease is empty")
+	}
+	v := PRVersion{}
+	if containsOnly(s, numbers) {
+		if hasLeadingZeroes(s) {
+			return PRVersion{}, fmt.Errorf("Numeric PreRelease version must not contain leading zeroes %q", s)
+		}
+		num, err := strconv.ParseUint(s, 10, 64)
+
+		// Might never be hit, but just in case
+		if err != nil {
+			return PRVersion{}, err
+		}
+		v.VersionNum = num
+		v.IsNum = true
+	} else if containsOnly(s, alphanum) {
+		v.VersionStr = s
+		v.IsNum = false
+	} else {
+		return PRVersion{}, fmt.Errorf("Invalid character(s) found in prerelease %q", s)
+	}
+	return v, nil
+}
+
+// IsNumeric checks if prerelease-version is numeric
+func (v PRVersion) IsNumeric() bool {
+	return v.IsNum
+}
+
+// Compare compares two PreRelease Versions v and o:
+// -1 == v is less than o
+// 0 == v is equal to o
+// 1 == v is greater than o
+func (v PRVersion) Compare(o PRVersion) int {
+	if v.IsNum && !o.IsNum {
+		return -1
+	} else if !v.IsNum && o.IsNum {
+		return 1
+	} else if v.IsNum && o.IsNum {
+		if v.VersionNum == o.VersionNum {
+			return 0
+		} else if v.VersionNum > o.VersionNum {
+			return 1
+		} else {
+			return -1
+		}
+	} else { // both are Alphas
+		if v.VersionStr == o.VersionStr {
+			return 0
+		} else if v.VersionStr > o.VersionStr {
+			return 1
+		} else {
+			return -1
+		}
+	}
+}
+
+// PreRelease version to string
+func (v PRVersion) String() string {
+	if v.IsNum {
+		return strconv.FormatUint(v.VersionNum, 10)
+	}
+	return v.VersionStr
+}
+
+func containsOnly(s string, set string) bool {
+	return strings.IndexFunc(s, func(r rune) bool {
+		return !strings.ContainsRune(set, r)
+	}) == -1
+}
+
+func hasLeadingZeroes(s string) bool {
+	return len(s) > 1 && s[0] == '0'
+}
+
+// NewBuildVersion creates a new valid build version
+func NewBuildVersion(s string) (string, error) {
+	if len(s) == 0 {
+		return "", errors.New("Buildversion is empty")
+	}
+	if !containsOnly(s, alphanum) {
+		return "", fmt.Errorf("Invalid character(s) found in build meta data %q", s)
+	}
+	return s, nil
+}
diff --git a/vendor/github.com/blang/semver/sort.go b/vendor/github.com/blang/semver/sort.go
new file mode 100644
index 00000000..e18f8808
--- /dev/null
+++ b/vendor/github.com/blang/semver/sort.go
@@ -0,0 +1,28 @@
+package semver
+
+import (
+	"sort"
+)
+
+// Versions represents multiple versions.
+type Versions []Version
+
+// Len returns length of version collection
+func (s Versions) Len() int {
+	return len(s)
+}
+
+// Swap swaps two versions inside the collection by its indices
+func (s Versions) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+// Less checks if version at index i is less than version at index j
+func (s Versions) Less(i, j int) bool {
+	return s[i].LT(s[j])
+}
+
+// Sort sorts a slice of versions
+func Sort(versions []Version) {
+	sort.Sort(Versions(versions))
+}
diff --git a/vendor/github.com/blang/semver/sql.go b/vendor/github.com/blang/semver/sql.go
new file mode 100644
index 00000000..eb4d8026
--- /dev/null
+++ b/vendor/github.com/blang/semver/sql.go
@@ -0,0 +1,30 @@
+package semver
+
+import (
+	"database/sql/driver"
+	"fmt"
+)
+
+// Scan implements the database/sql.Scanner interface.
+func (v *Version) Scan(src interface{}) (err error) {
+	var str string
+	switch src := src.(type) {
+	case string:
+		str = src
+	case []byte:
+		str = string(src)
+	default:
+		return fmt.Errorf("Version.Scan: cannot convert %T to string.", src)
+	}
+
+	if t, err := Parse(str); err == nil {
+		*v = t
+	}
+
+	return
+}
+
+// Value implements the database/sql/driver.Valuer interface.
+func (v Version) Value() (driver.Value, error) {
+	return v.String(), nil
+}