Update .gitignore file.
Updates:
  - Move to a completely OAuth2-based authentication system.
  - Remove sensitive information from repository in preperation for
    public release.
  - Use Angular Bootstrap Modal service instead of regular Bootstrap
    modals.
  - Move spinner into it's own directive for cleanliness.
  - Break the Github service into multiple services. The Github service
    is now solely for authentication and getting the authenticated user.
  - Move back to the old UI style where the panel is on the right side
    of the screen. Having it at the bottom caused more problems than it
    solved.
  - Add Grunt tasks for releasing source and releasing production. I may
    add more tasks in the future to make the extension run faster in
    prod.

Rawr. It's 4:43 AM and I am a Food Lion.