0.2rc2: The next big thing™

* Uses SQLite to store everything
* Refactors the views, cli, tasks, ...
* Adds new check: the first line should not end with a dot
* Adds alternative signatures, e.g. `Reported-by`
* Updates rq to 0.4.6 (enabling `timeout`)
* Adds support of PEP257 `match` and `match_dir`.
* Adds Sphinx documentation
* Supports pending states
* Supports `push` events
* Supports multi repositories (from multi-users)
* Supports a token per user (so they can delete the comment at their place too)
* Adds alembic migrations
* Replacing nose by pytest
* _..._

### known issues

* [x] on `push` events, tests are performed on deleted files.
* [x] `push` events don't care about `wip`.
* [x] buggy sorting.
* [x] coveralls is confused.