author topic model support

[eamonnmag]

It would be great to have support for visualization of author topic models. At present you will get this error:

/Users/eamonnmaguire/.virtualenvs/coref3/lib/python3.5/site-packages/pyLDAvis/gensim.py in _extract_data(topic_model, corpus, dictionary, doc_topic_dists)
     40           gamma = topic_model.inference(corpus)
     41       else:
---> 42           gamma, _ = topic_model.inference(corpus)
     43       doc_topic_dists = gamma / gamma.sum(axis=1)[:, None]
     44 

TypeError: inference() missing 3 required positional arguments: 'author2doc', 'doc2author', and 'rhot'

This would require some changes to the UI I'd imagine to allow for selection of an author to view their topics.

[lg8897203]

#112