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/tests/attrdict.py

@@ -3,7 +3,6 @@ class AttrDict(dict):
 
     This should only be used to mock objects for unit testing. Please do not use this outside of qmk.tests.
     """
-
     def __init__(self, *args, **kwargs):
         super(AttrDict, self).__init__(*args, **kwargs)
         self.__dict__ = self

lib/python/qmk/tests/test_cli_commands.py

@@ -7,7 +7,7 @@ def check_subcommand(command, *args):
 
 
 def test_cformat():
-    assert check_subcommand('cformat', 'tmk_core/common/backlight.c').returncode == 0
+    assert check_subcommand('cformat', 'tmk_core/common/keyboard.c').returncode == 0
 
 
 def test_compile():

lib/python/qmk/tests/test_qmk_path.py

@@ -10,4 +10,4 @@ def test_keymap_onekey_pytest():
 
 def test_normpath():
     path = qmk.path.normpath('lib/python')
-    assert path == os.environ['ORIG_CWD'] + '/lib/python'
+    assert path == os.path.join(os.environ['ORIG_CWD'], 'lib/python')