µGame 10 firmware with CircuitPython 3.0.2

This is an update of the µGame 10 firmware, using CircuitPython 3.0.2 The changes include:

• Now ships with CircuitPython 3.0.2, which has a number of bug fixes and performance improvements.
• Updated and improved gamepad library for handling the button presses.
• Rewritten ugame.Audio class to handle the new way CircuitPython plays wave files.
• A new art module including built-in assets for games. For now it only has assets for Vacuum Invaders.

Please note that while most games should be compatible, games that handled sound on their own (not through the Audio class) and games that require compiling to .mpy file will need to be updated.