a simple PlantsVsZombies game

• implement plants: sunflower, peashooter, wallnut, snowpeashooter, cherrybomb, threepeashooter, chomper, puffshroom, potatomine.
• implement zombies: zombie, flagzombie, coneheadzombie, bucketheadzombie, newspaperzombie.
• use json file to store level data (e.g.position and time of zombies, background info)

• Python 3.7
• Python-Pygame 1.9

$ python main.py

• use mouse to collect sun, select the plant cards and seed the plant