Added attr_acc and initialize for new topping.
Added failing test checking if topping is vegetarian or not.
Add vegetarian boolean keyword to Toppings initialize method.
Add failing test for initializing a new pizza with an array of toppings.
Create initialize method for Pie class.
Add failing test for creating a cheese only pie with no toppings passed as arguments.
Update initialize method for class Pie to default to cheese only when no toppings are given.