compile should have option to commit & push

[zramsay]

The standardized commit msgs from themis-contract update are fantastic and it would be great to have them for compile as well ... and also to avoid have to git add contract.pdf \ git commit -m "compiled the contract" \ git push origin theBranch.

As discussed in #79, I'm of the view that all these options should be off by default and enabled with either flags or environment variables