Feature/auth and profile management

This PR introduced OAuth based authentication and routes to handle the login process and initial profile generation.

@todo: style the form a bit, discuss scope for skills/training/education drop downs, add save functionality and profile editing (once we get the scope nailed down)

IMPORTANT! You must provide an application client/secret in the oauth config. The URL for the callback is:

`http://mentorapp.dev/api/v1/oauth`