Shop and Balancing Update

Hello! I've got a new update here. Features:

-Balanced game speed (game speed is now half as fast)

-Added shop

-Added Tamiflu (stops virus from leaving infected cell)

-Added penicillin (Kills bacterial cell)

Future goals:

Antibiotic-resistant bacteria

B cell training (model how B cells randomly get antibodies which match a certain bacteria or virus)

Vaccines