add methods to Word2Vec for word-word similarity

add a method to Word2Vec that returns the vector representation of a
word.
add a method to Word2Vec that computes the similarity between two words.

Signed-off-by: Ghassen Hamrouni <ghamrouni.iptech@gmail.com>
add methods to Word2Vec for word-word similarity

add a method to Word2Vec that returns the vector representation of a
word.
add a method to Word2Vec that computes the similarity between two words.

Signed-off-by: Ghassen Hamrouni <ghamrouni.iptech@gmail.com>
Merge pull request #124 from GHamrouni/develop

Add two methods to Word2Vec for word-word similarity