Added fields to User model

`projects_available`
Holds the number of projects the user can currently create

`active_project_id`
Holds the ID of the user’s currently active project
Fixed ProjectsController

None of the methods were actually inside the class
Fleshed out UsersController

Now returns a user in JSON!
Fleshed out ProjectsController

Now outputs data!
Added FriendlyId to Project model