python setup.py test is soon to be deprecated

[sjunges]

See https://github.com/pypa/setuptools/issues/1684

I think that we should therefore consider alternatives.

[volkm]

Since the test command currently does nothing more than call pytest, I think that should be no problem. I see two options how to handle this:

1. Perform the following steps instead to use pytest:

   pip install pytest
   py.test
   

   We just have to make sure that it will still be possible to give the pytest options in setup.cfg.

2. The second options would be to migrate to tox.

[volkm]

The latest version of setuptools has now removed the test command and CI now fails. This makes the replacement urgent.