Automagic Downloaders & LSTM for Translation

The following examples from the book should now work:

>>> nlpia.loaders.get_data('deu')  # German-English sentence pairs for `nlpia.translate` LSTM models 
>>> nlpia.loaders.get_data('imdb')  # DataFrame of IMDB movie reviews with ratings

Also, a multi-language international translation character-based LSTM model can be built using the new nlpia.translate module:

>>> from nlpia.translate import *
>>> model = main('spa', n=10000, epochs=100, batch_size=64, num_neurons=128)
Train on 9000 samples, validate on 1000 samples
Epoch 1/100

Also, the base-requirements.txt now includes Keras, tensorflow-gpu, SpaCy, and regex.