Add test files for orders_controller and order model
refactor order_items_controller#load_order
Additional refactoring of order_items_controller#load_order
fix merge conflicts in spec/features/order_feature_spec.rb
fix merge conflict in spec/features/order_feature_spec.rb
complete implementation of maintaing order through log out and back in

refactor order_items_controller#find_or_create_order
Refactor order#total
Merge branch 'log-out-in-orders'