Added checkout routes for orders & cart_items
Updated when CreditCard model was generated

Created table credit_cards in database
Added column credit_card_id to orders table in database
Default test file created with model generation
Default test\fixtures file created with model generation
Migration from creation of CreditCard model
Migration - add. of credit_card_id col. to orders
New test for checkout form
Model generated
Unnecessary at this time
New Order & Shopping Cart Session
Added method to compute total price of order
product.price not price in total_price method
Added link_to Checkout button
Took out date input experiment
Shows 4-column table order summary
Just a header tag for now!