Implement a Doc2Vec mechanism for documents comparisson

[liadmagen]

Create an easy way to compare documents through their contents, using Doc2Vec
Read this blog post for background and details about this algorithm:
https://medium.com/scaleabout/a-gentle-introduction-to-doc2vec-db3e8c0cce5e

To do so, you should first - have a REST API methods to:

• convert a single document to a vector
• convert multiple documents (array of strings) to an array of vectors
• given two vectors, return the distance between them
• given two documents, convert them to vectors and return the distance (similarity) between them