wip: registration process

Working on customizing user devise model.

Took a little research to learn about "strong" parameters which is Rails's answer to [mass assignment vulnerability](http://en.wikipedia.org/wiki/Mass_assignment_vulnerability).  (Basically you have to explicitly `permit` the props on `User` that get filled during a `POST` or `PUT` on the server.

How-to: http://blog.12spokes.com/web-design-development/adding-custom-fields-to-your-devise-user-model-in-rails-4/