This fixes the following issue related to encoding on linux systems. Add
`universal_newlines=True` to subprocess.
<class 'TypeError'>
☒ a bytes-like object is required, not 'str'
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/milc.py", line 564, in __call__
return self.__call__()
File "/usr/local/lib/python3.7/site-packages/milc.py", line 569, in __call__
return self._entrypoint(self)
File "$HOME/qmk_firmware/lib/python/qmk/cli/doctor.py", line 56, in doctor
for line in mm_check.stdout.split('\n'):
TypeError: a bytes-like object is required, not 'str'