Clean up checks and logics that are unnecessary due to MILC updates.
Use pathlib instead of os.path for readability.
Use the 'pytest' keyboard for the tests.
Add community layout for 'handwired/onekey/pytest' so we can test
community layouts.
Instead of using regexes and globbing to find the rules.mk and keymap.c
files, walk the directory tree to find them.
Also, do away with the concept of revision.
