Implement BERT, ElMo and ULMFit - Transfer learning for NLP models
See fast.ai

  - announcement: http://nlp.fast.ai/classification/2018/05/15/introducting-ulmfit.html
  - paper: https://arxiv.org/abs/1801.06146
  - course: http://course.fast.ai/lessons/lesson10.html

![image](https://user-images.githubusercontent.com/22738317/44593584-1a366080-a7c4-11e8-826f-78e7c057e17e.png)
