Add basic user model and tests.
Add user_id to groups and colors, update uniqueness tests
Generate users controller and provide signup route.
Implement new action for users, create signup page.
Implement user create action.
Add tests for matching password confirmation.
Add email format validation.
Force SSL in production mode.
Validate unique emails and downcase before saving.
Add index to users email.
Add indexes to user foreign keys.
Update the seeds files for users.
Speed up tests by reducing bcrypt cost.
Merge pull request #53 from msrose/feature/user-signup

Feature/user signup