Computes order total for zero pizzas
Added quantity to Order and renamed Pizza Manager to CashRegister
Introduced OrderTaker and injected it into Order
orderTaker prompts user for cheese pizza quantity
orderTaker reads and returns number of pizzas from user
created Pizza class and order has pizzas instead of quantity
refactored Order class to calculate total price for multiple pizzas
Pizzas have quantity and their total price is quantity times price