Bug/remove confirmable

This branch is based on https://github.com/wetap/wetap-api/pull/19 so merge that first!  Take a look at a diff of actual changes [here](https://github.com/wetap/wetap-api/compare/feature/style_login_pages...bug/remove_confirmable)

This removes confirmation of the user accounts. The motivation is that the API is not properly integrated into what [devise confirmable](http://rubydoc.info/github/plataformatec/devise/master/Devise/Models/Confirmable) provides. So wetap functionality (fountain creation etc) _works_ even though the User is in an unconfirmed state. 

The solution is to drop `:confirmable` from the user model and implement it as a proper feature further down the road.