add vendor & update README.md

vendor/github.com/gin-gonic/autotls/README.md

@@ -0,0 +1,67 @@
+# autotls
+
+[![Build Status](https://travis-ci.org/gin-gonic/autotls.svg?branch=master)](https://travis-ci.org/gin-gonic/autotls) 
+[![Go Report Card](https://goreportcard.com/badge/github.com/gin-gonic/autotls)](https://goreportcard.com/report/github.com/gin-gonic/autotls)
+[![GoDoc](https://godoc.org/github.com/gin-gonic/autotls?status.svg)](https://godoc.org/github.com/gin-gonic/autotls)
+[![Join the chat at https://gitter.im/gin-gonic/autotls](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/gin-gonic/autotls?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+Support Let's Encrypt for a Go server application.
+
+## example
+
+example for 1-line LetsEncrypt HTTPS servers.
+
+[embedmd]:# (example/example1.go go)
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/gin-gonic/autotls"
+	"github.com/gin-gonic/gin"
+)
+
+func main() {
+	r := gin.Default()
+
+	// Ping handler
+	r.GET("/ping", func(c *gin.Context) {
+		c.String(200, "pong")
+	})
+
+	log.Fatal(autotls.Run(r, "example1.com", "example2.com"))
+}
+```
+
+example for custom autocert manager.
+
+[embedmd]:# (example/example2.go go)
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/gin-gonic/autotls"
+	"github.com/gin-gonic/gin"
+	"golang.org/x/crypto/acme/autocert"
+)
+
+func main() {
+	r := gin.Default()
+
+	// Ping handler
+	r.GET("/ping", func(c *gin.Context) {
+		c.String(200, "pong")
+	})
+
+	m := autocert.Manager{
+		Prompt:     autocert.AcceptTOS,
+		HostPolicy: autocert.HostWhitelist("example1.com", "example2.com"),
+		Cache:      autocert.DirCache("/var/www/.cache"),
+	}
+
+	log.Fatal(autotls.RunWithManager(r, &m))
+}
+```