Add a failing test for Pizza::Topping.initialize.
Add ability to instantiate a new pizza topping
Add failing text to check if a topping is vegetarian
Add boolean check for whether or not pizza topping is vegetarian, defaults to meaty goodness
Add failing test for setting toppings
Fix line missing from spec. Add .initialize records all toppings in Pie class
Add failing test to check for default topping = cheese
Added default topping of cheese for no other toppings passed in