Changes from Esteve Boix:

- Added two tables to the database: STATUS and STATUSTRACK, and new field to the TASK table to hold the current status.
- Each task can have a history of status (in STATUSTRACK) that can be viewed with the AngularJS app.
- The migrations reflect those changes, together with the updated dump for the tests.
- I've had no much time for the tests, sorry, they are incomplete.
- I've updated the models to use "hasOne" relationships.
- I've created new controllers to assign statuses and handling the messaging using Twilio's API.