Improve EloComparator

- export constructor instead of weird function
- don't use global variables
- only use tabs for indention
- don't use private functions
-
Replace feelerController with ButtonController
Remove unused playerController
Improve GameController

- don't use global variables
- don't create feelers/buttons, use passed-in values
- various other fixes
Rewrite CardReader to use PN532 board
Remove unnecessary leaderboard module
Don't use global variables in stats module
Create Button class
Improve Game model
Improve Player model
Refactor app and server

- move app logic from server into app module
- convert server into class object
Update dependencies to work with Raspberry Pi
Add a few scripts for testing
Improve home template
Alter config example for use with Raspberry Pi
Rebuild frontend