Migrate from dep to go module

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/modern-go/reflect2/.gitignore

@@ -0,0 +1,2 @@
+/vendor
+/coverage.txt

vendor/github.com/modern-go/reflect2/.travis.yml

@@ -0,0 +1,15 @@
+language: go
+
+go:
+  - 1.8.x
+  - 1.x
+
+before_install:
+  - go get -t -v ./...
+  - go get -t -v github.com/modern-go/reflect2-tests/...
+
+script:
+  - ./test.sh
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)

vendor/github.com/modern-go/reflect2/Gopkg.lock

@@ -0,0 +1,15 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  name = "github.com/modern-go/concurrent"
+  packages = ["."]
+  revision = "e0a39a4cb4216ea8db28e22a69f4ec25610d513a"
+  version = "1.0.0"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "daee8a88b3498b61c5640056665b8b9eea062006f5e596bbb6a3ed9119a11ec7"
+  solver-name = "gps-cdcl"
+  solver-version = 1

vendor/github.com/modern-go/reflect2/Gopkg.toml

@@ -0,0 +1,35 @@
+# Gopkg.toml example
+#
+# Refer to https://golang.github.io/dep/docs/Gopkg.toml.html
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#   name = "github.com/x/y"
+#   version = "2.4.0"
+#
+# [prune]
+#   non-go = false
+#   go-tests = true
+#   unused-packages = true
+
+ignored = []
+
+[[constraint]]
+  name = "github.com/modern-go/concurrent"
+  version = "1.0.0"
+
+[prune]
+  go-tests = true
+  unused-packages = true

vendor/github.com/modern-go/reflect2/README.md

@@ -0,0 +1,71 @@
+# reflect2
+
+[![Sourcegraph](https://sourcegraph.com/github.com/modern-go/reflect2/-/badge.svg)](https://sourcegraph.com/github.com/modern-go/reflect2?badge)
+[![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/modern-go/reflect2)
+[![Build Status](https://travis-ci.org/modern-go/reflect2.svg?branch=master)](https://travis-ci.org/modern-go/reflect2)
+[![codecov](https://codecov.io/gh/modern-go/reflect2/branch/master/graph/badge.svg)](https://codecov.io/gh/modern-go/reflect2)
+[![rcard](https://goreportcard.com/badge/github.com/modern-go/reflect2)](https://goreportcard.com/report/github.com/modern-go/reflect2)
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://raw.githubusercontent.com/modern-go/reflect2/master/LICENSE)
+
+reflect api that avoids runtime reflect.Value cost
+
+* reflect get/set interface{}, with type checking
+* reflect get/set unsafe.Pointer, without type checking
+* `reflect2.TypeByName` works like `Class.forName` found in java
+
+[json-iterator](https://github.com/json-iterator/go) use this package to save runtime dispatching cost.
+This package is designed for low level libraries to optimize reflection performance.
+General application should still use reflect standard library.
+
+# reflect2.TypeByName
+
+```go
+// given package is github.com/your/awesome-package
+type MyStruct struct {
+	// ...
+}
+
+// will return the type
+reflect2.TypeByName("awesome-package.MyStruct")
+// however, if the type has not been used
+// it will be eliminated by compiler, so we can not get it in runtime
+```
+
+# reflect2 get/set interface{}
+
+```go
+valType := reflect2.TypeOf(1)
+i := 1
+j := 10
+valType.Set(&i, &j)
+// i will be 10
+```
+
+to get set `type`, always use its pointer `*type`
+
+# reflect2 get/set unsafe.Pointer
+
+```go
+valType := reflect2.TypeOf(1)
+i := 1
+j := 10
+valType.UnsafeSet(unsafe.Pointer(&i), unsafe.Pointer(&j))
+// i will be 10
+```
+
+to get set `type`, always use its pointer `*type`
+
+# benchmark
+
+Benchmark is not necessary for this package. It does nothing actually.
+As it is just a thin wrapper to make go runtime public. 
+Both `reflect2` and `reflect` call same function 
+provided by `runtime` package exposed by go language.
+
+# unsafe safety
+
+Instead of casting `[]byte` to `sliceHeader` in your application using unsafe.
+We can use reflect2 instead. This way, if `sliceHeader` changes in the future,
+only reflect2 need to be upgraded.
+
+reflect2 tries its best to keep the implementation same as reflect (by testing).

vendor/github.com/modern-go/reflect2/test.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > coverage.txt
+
+for d in $(go list github.com/modern-go/reflect2-tests/... | grep -v vendor); do
+    go test -coverprofile=profile.out -coverpkg=github.com/modern-go/reflect2 $d
+    if [ -f profile.out ]; then
+        cat profile.out >> coverage.txt
+        rm profile.out
+    fi
+done

vendor/github.com/modern-go/reflect2/type_map.go

@@ -4,6 +4,7 @@ import (
 	"reflect"
 	"runtime"
 	"strings"
+	"sync"
 	"unsafe"
 )
 
@@ -15,10 +16,17 @@ func typelinks1() [][]unsafe.Pointer
 //go:linkname typelinks2 reflect.typelinks
 func typelinks2() (sections []unsafe.Pointer, offset [][]int32)
 
-var types = map[string]reflect.Type{}
-var packages = map[string]map[string]reflect.Type{}
+// initOnce guards initialization of types and packages
+var initOnce sync.Once
+
+var types map[string]reflect.Type
+var packages map[string]map[string]reflect.Type
+
+// discoverTypes initializes types and packages
+func discoverTypes() {
+	types = make(map[string]reflect.Type)
+	packages = make(map[string]map[string]reflect.Type)
 
-func init() {
 	ver := runtime.Version()
 	if ver == "go1.5" || strings.HasPrefix(ver, "go1.5.") {
 		loadGo15Types()
@@ -90,11 +98,13 @@ type emptyInterface struct {
 
 // TypeByName return the type by its name, just like Class.forName in java
 func TypeByName(typeName string) Type {
+	initOnce.Do(discoverTypes)
 	return Type2(types[typeName])
 }
 
 // TypeByPackageName return the type by its package and name
 func TypeByPackageName(pkgPath string, name string) Type {
+	initOnce.Do(discoverTypes)
 	pkgTypes := packages[pkgPath]
 	if pkgTypes == nil {
 		return nil