linters => imhotep_linters to prevent name collision.
A maybe-start to a better API?
Merge branch 'master' into higher-level-tool-api
better fleshing out higher level interface.

Need to think more about pylint.
Started working on adding config file support, currently untested.
Added import for the repositories, and fixed some small things.
Updated docs
Changed the config to use dictionary.get cus heh I forgot about it.

I left the cache-directory how it was, because it is easier to deal with,
when we want linting to be ephemeral.
pep8 violation fixes
hard exit it no github credentials are provided
extract config loading into function & reorganize variable population
Close the config file after reading it.
pull github requester into its own module.
commit application & diffs is the responsibility of repositories

Also, diffs and commit applications are also separate concerns.
defaults for config file location, since it not existing is idempotent.
Now with passing tests.
Attention towards testing & pep8
test for repomanager fetching correct repo class.
Test repo cleanup with mock executor.
Moar tests.