由于Ruby 2.0.0已不赞成使用DL小提琴运动。您可以在此处找到您的***答案，以摆脱我刚才也遇到的警告消息。祝你好运！

Since Ruby 2.0.0 deprecated DL to move towards fiddle movement. Your best answer can be found here to get rid of the warning message that I also encountered a while ago. Good luck!