use submodule

vendor/github.com/gorilla/websocket/client_clone.go

@@ -1,16 +0,0 @@
-// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build go1.8
-
-package websocket
-
-import "crypto/tls"
-
-func cloneTLSConfig(cfg *tls.Config) *tls.Config {
-	if cfg == nil {
-		return &tls.Config{}
-	}
-	return cfg.Clone()
-}