Added Russian language

[bekerov]

Corrected swagger API url Updated readme.md

[Tpt]

You probably want to add "Russian" to install-syntaxnet-debian.sh and maybe also to the Swagger UI defined in flask_server.py

[Tpt]

I read in [1] that Russian does not have text segmentation yet. I'm afraid it's a blocker (except if the documentation is outdated).

[1] https://github.com/tensorflow/models/blob/master/syntaxnet/universal.md

[Tpt]

Sadly no tokenizer for Russian :-(. So, this PR won't work as it is. We have to find/train a tokenizer.

[bekerov]

No problem .)