[Task] User roles

[skrix]

Brief: User should be able to choose a role mentor/mentee
Description:
First Scenario:
- User sign-in/up via GitHub account
- User clicks on the profile settings icon
- User redirected to settings page with select role dropdown on the top of it
- User clicks on the dropdown and sees the options mentor/mentee below it
- User choose a role which he wants
P.S. For roles recommend to use rollify gem

Second Scenario:
- User go to the sign-up page and see two buttons here "Sign up as mentor" and "Sign up as mentee"
- User clicks on a button which he/she choose
- User sign-up via GitHub account
- User redirected to the home page
- Role of this user is already set
P.S. For this kind of flow use STI with type for devise models and custom sign-up devise controller

[andrzejkrzywda]

@skrix Thanks for the description!

I think we will ship live even without this working (see the MVP milestone), but just after that I'd be happy to discuss the details of your suggestions (overall looks fine!).

[oxanayoxana]

This is kind of fixed in these two ones https://github.com/arkency/find-open-source-mentor/pulls