Login System and Security System

The login system and security is now working, pair-programmed with @erthh.

:heart_eyes: :blush: :relaxed: :sweat: :tired_face: :dizzy_face:

Complete with tests (but still need acceptance test from @armse).

Some open issue is: #52 :anger: :exclamation: :collision: 

:yellow_heart: :heart: :green_heart: :blue_heart: :sparkling_heart: