add fasttext jpn language model

[wvanamstel]

Added fasttext Japanese language model in its own directory. Renamed the original w2v src directory. To be done: change Dockerfile to reflect these changes.

[vampolo]

Hey @wvanamstel, thanks for the contribuition.
I think we should make a stronger folder change here. What I mean is to have 2 folders in the root: word2vec and fasttext. Each of those have their entrypoint.sh and src folder with the relevant changes.
Do you think you can make those changes? Thanks!