Replace gorilla with melody for websocket API (#1205)

vendor/gopkg.in/olahol/melody.v1/doc.go

@@ -0,0 +1,22 @@
+// Copyright 2015 Ola Holmström. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package melody implements a framework for dealing with WebSockets.
+//
+// Example
+//
+// A broadcasting echo server:
+//
+//  func main() {
+//  	r := gin.Default()
+//  	m := melody.New()
+//  	r.GET("/ws", func(c *gin.Context) {
+//  		m.HandleRequest(c.Writer, c.Request)
+//  	})
+//  	m.HandleMessage(func(s *melody.Session, msg []byte) {
+//  		m.Broadcast(msg)
+//  	})
+//  	r.Run(":5000")
+//  }
+package melody