Feature/w2v fix

[dafajon]

sadedegel/bblock/cli/__main__.py

• gensim interface for tranining needed updates on certain argument names.

sadedegel/bblock/utils.py

• tr_lower receives Token objects while trying to form the vocabulary. Handle Token receiving case for tr_lower and tr_upper methods.

sadedegel/bblock/vocabulary.py

• Fix gensim related argument and instance method names.
• number of indices of tokens that has vectors are less than all number of unique tokens. They are stored in two separate groups in h5py vocabulary dumps. I noticed when I called has_vector attribute of a Token instance, it queries the has_vector group with an index taken from word group. As a result wrong boolean value is returned to the user.
• I fixed this by separating id2feat and vice versa for all tokens and tokens that have vector.

tests/token/test_vectors.py

• Implement test indices, word-id match for both mappers.
• Implement test for vector access.

README.md

• Update with the description of vocabulary dumps and w2v training.