remove sign in once message
generate UserMailer
setup_mail initializer
new_follower mail action and view
remove welcome_email.*
add new_follower action to relationship controller
add argument to new_follower action and view
updated mail gem
add mail interceptor
add attachment to new_follower
add notification to users
email user if notification true
remove attachment from mailer
add notification to user form view
validation for user_name
username added to user edit views and controller
update user_pages_spec with user_name validation
updated factories.rb to remove password duplication
refactor notification as a user method
tests for mailer