add missing build tag.

Author: shogo82148

driver_go110_test.go

@@ -6,6 +6,8 @@
 // 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 go1.10
+
 package mysql
 
 import (