[Issue #1] Facebook Login

  - Added facebook login using omniauth
  - Updated home#index with facebook login in navbar
  - Specs coverage for fb-login and user model
[Issue #1] Fixes

  - Fixes in user models and specs related
  - Removed unnecessary files
  - Fixed some typos
Merge pull request #6 from insignia4u/Issue#1

[Issue #1] Facebook Login