exec: rails generate model User name:string email:string
exec: rake db:migrate
add testcases
add validation in User model
comments out validation in User model
add testcases
comments in
add testcase
add validation for email at User model
add validation for long name at User model
add testcase
fix testcase
add testcase for User.email validation
add validation to User.model
add testcase for User.email validation
add validation to User.model
change testcase for email ignorecase
change validation for ignorecase of User.email
exec: rails generate migration add_index_to_users_email
create migration for DB layer validation of User.email