PH & TM - Rails Forms and Associations - Paired assignment - Week 5

A marathon of coding that has all but the Orders epic complete. It's not pretty, but it's pretty functional.
This is the precise situation in which you would want to have those relationships specified in the model. In user.rb: `belongs_to :default_billing_address, :class_name => "Address"`; and here: <%= user.default_billing_address %>.