add vendor packages避免用户网络太慢无法下载编译

vendor/github.com/go-sql-driver/mysql/utils_legacy.go

@@ -0,0 +1,18 @@
+// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
+//
+// Copyright 2017 The Go-MySQL-Driver Authors. All rights reserved.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// +build !go1.7
+
+package mysql
+
+import "crypto/tls"
+
+func cloneTLSConfig(c *tls.Config) *tls.Config {
+	clone := *c
+	return &clone
+}