Users can sign-up with Monban

https://trello.com/c/t8jfPfDZ/35-as-a-user-i-should-be-able-to-log-in-to-the-website

![selection_020](https://cloud.githubusercontent.com/assets/8248100/5073177/0e4e0196-6e4e-11e4-9eaf-a5298ab59875.png)