WIP
WIP renaming HarryPotterBooks to ShoppingCart and creating HarryPotterBooks to be a hashmap of books to book count which calculates price
WIP initializing bookTypes to empty before using them
WIP No null pointers, but logic for when to discount is backwards with regards to book count
WIP failing on two books of same type
WIP: one book should be 8, not 16
WIP
Fixed bug in calculateBookTypes
Removing dead code/comments