http://www.cnblogs.com/rucwxb/p/10277217.html
https://zhuanlan.zhihu.com/p/49271699
https://ai.googleblog.com/2017/08/transformer-novel-neural-network.html
https://www.jianshu.com/p/ef41302edeef
https://github.com/google-research/bert
https://blog.youkuaiyun.com/yujianmin1990/article/details/85221271