Bump to Devise 3.2.2
Remove :token_authenticatable from model, as Devise 3.1 deprecated it
Remove Spree::User.anonymous!

This appears to no longer have a use within Spree itself. Orders seem content to have an email associated with them, but no user associated
Use EmailValidator.valid? to check if email is valid in CheckoutController#update_registration
Remove token_authentication_key, given it is now deprecated
Return warning for when people have not configured Devise.secret_token
Remove ancient commented out code from admin/users_controller
Update user password reset to work with Devise 3.2.2
Remove attr_accessible comments from User model
Order email tests already exist within core

No need to have them duplicated in auth as well
Spree::UserMailer tests now need to pass TWO arguments
Remove unnecessary pending test from users_controller_spec
Fix argument list expected for reset_password_instructions in user_spec
Clear all AM deliveries before all tests
Add installer to setup Devise's secret_token