go vet && golint

sqlite3_go18.go

@@ -1,3 +1,8 @@
+// Copyright (C) 2014 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
 // +build go1.8
 
 package sqlite3
@@ -6,7 +11,7 @@ import (
 	"database/sql/driver"
 	"errors"
 
-	"golang.org/x/net/context"
+	"context"
 )
 
 // Ping implement Pinger.