Add User model
Migrate first migration
Add tests for presence of name and email in User
Add validations for presence of name and email in User
Add name length validation and test
Add test for valid email address format
Add validation for email using regex
Add test for email uniqueness
Add validation for email uniqueness
Add migration for index on email
Convert email to lowercase
Add Bcrypt gem
Test for presence of password
Add password migration
Add tests for password
Add tests for password authentication
Add has_secure_password and minimum length
Add test for downcasing email address
Add extra test for invalid email
Fix valid email regex