Small CLI cleanups

* yapf changes
* Fix the cformat test
* Make the normpath test work when run from /
* `qmk config`: Mark `--read-only` as arg_only

lib/python/qmk/errors.py

@@ -1,6 +1,5 @@
 class NoSuchKeyboardError(Exception):
     """Raised when we can't find a keyboard/keymap directory.
     """
-
     def __init__(self, message):
         self.message = message