Add Devise auth, migrate to Foundation 5.
Update layout, styles.
Implement Devise registration, sessions on User model.

- Break down layout into partials for flash notices, session status.
- Add Foundation icon font to /vendor/assets.
- Current spec status: 6 examples, 0 failures in 0.09745 seconds.
Merge pull request #1 from sleepingkingstudios/devise-and-foundation-5

Implement Devise registration, sessions on User model.