User model implementation

[trungams]

Following the discussion in issue #10. We will now try to extend our user model to support password authentication.

Feature/Enhancement Description

OAuth is being used for login so that new users don't have to register for a new account providing that they have a WCA account and ID. This puts a limit on who can sign in to our website, and some people might not need a WCA account in order to create meetup events.

Tasklists Suggestion

• Extend our current User (Cuber) model to have a password field.
• Implement registering.
• Implement login with password.
• Allow registered user to connect with their WCA account to sign up for events and competitions.
• Email verification. THIS IS IMPORTANT

Additional Comments

[trungams]

Got basically everything in 8b6e643. We will see if they work with the event + registration tomorrow.