* align run() wrapper functionality and naming with subprocess.run()
  introduced in Python 3.5, making it a thin wrapper now
* change parameter names for consistency with subprocess.run() and even
  subprocess_tee which is re-implemented here in a straightforward way
* align CommandOutput with subprocess.CompletedProcess for consistency
* finally support both stream and capture of stdout/stderr using asyncio
  with tee=True (new default, replaces old direct parameter)
* don't log errors in run(), leave that to caller - simpler code

Thanks to subprocess_tee authors for inspiration ❤

Closes: #68