:lollipop: Added .gitattributes & .gitignore files
Facebook login & DB edit

- Edit DB: (1) add more detailed fields for address. ; (2) add 'gender'
to user
- Add login with facebook: Let users authenticate using Facebook,
retrieve their public profiles and create accounts for them using the
retrieved information
Note: UI not optimized at the moment
Merge remote-tracking branch 'upstream/master'
Merge pull request #3 from nmduc/master

Facebook login added & some small DB modifications