Move SCM, runners and parser plugins to separate repositories

[jawher]

Please have a look at this PR as I need your feedback on it before I finish moving the remaining parts.

What's already done:

• Move Git plugin to bazooka-ci/bazooka-scm-git
• Move Mercurial plugin to bazooka-ci/bazooka-scm-hg
• Move the Golang support plugin (parser and runners) to bazooka-ci/bazooka-lang-go

What still needs to be done:

• Move the Java support plugin (parser and runners) to bazooka-ci/bazooka-lang-java
• Move the Python support plugin (parser and runners) to bazooka-ci/bazooka-lang-python
• Move the Node support plugin (parser and runners) to bazooka-ci/bazooka-lang-node

[julienvey]

I'm alright with the solution

• One repo per SCM
• One repo per language (parser + runner)

Don't forget to update docker hub repository ?

Any chance that with the current separation, we could have Docker hub automated build for language parsers ?