放弃 LSTM ?
http://tech.ifeng.com/a/20180829/45143909_0.shtml
https://arxiv.org/abs/1808.03867
https://arxiv.org/abs/1803.01271
https://towardsdatascience.com/the-fall-of-rnn-lstm-2d1594c74ce0
https://www.quora.com/Is-it-possible-to-train-a-RNN-on-a-single-extremely-long-sequence
https://arxiv.org/abs/1803.04831
https://deepmind.com/blog/wavenet-generative-model-raw-audio/