executed `rails generate model authorization`
added the name

according to the location 213 of the ebook, we just add the name
executed rake db:migrate
Make Authorization model belongs to user
add twitter consumer key and secret to the initializers/devise.rb
moved the secret and the key to the app_config.yml
created new omniauthcallbackscontroller to handle twitter callbacks
add omniauth_callbacks option to the routes
User model has_many Authorizations