Implement manual PR checking.
Only take the pull_request part of the payload.

This enables manual PR checking - a requested PR fetch only gets the pull_request part.
Ensure existence of storage directories.
Fix json parsing, and some cleanup. 

Comment out comment-style feedback functions.
Removes pesky pylint warnings.
Remove wrong TODO file - log output is already correctly redirected.
Flesh out Readme. Bump version to 0.2