generate User model
migrate User model
add tests to verify presence of email and name for user
add user model validation for email and name with tdd
add name length test and validation;
add email test and validation with regex
add email validation for uniqueness
add email case sensitivity validation
add test for email case sensitivity uniqueness
change name format for email case sensitivity uniqueness test
add index to user model for email column and set before_save callback to make email lowercase to ensure uniqueness
add bcrypt to Gemfile and Gemfile.lock
add password digest column to user model with test
add secure password and tests
add tests for secure password
add test for saving email address as downcase
rewrite before_save callback with bang method
update regex to catch abc@def..com as invalid emails, basically catch the two periods