[Commit] Move state class methods from PushJob to Commit.
[ManageController] Show commits instead of jobs.
[Rakefile] Make a note of it not working (I assume the db:migrate task aborts rake).
[PodVersion] Add methods under discussion.
[Commit] Add pushed_by method.

Unsure about the name. PodVersion#pushed_by => Commit, and Commit.pushed_by => PushJob seems weird.
[PodsController] Fix specs.
[ManageController] Fix specs.
[Commits] Add views index and show.
[ManageController] Add jobs#show action.
[PodsController] Fix action.