migrate from removed setuptools' test command

[stanislavlevin]

setup.py test is deprecated since setuptools 41.5.0:
https://setuptools.pypa.io/en/latest/history.html#v41-5-0

setuptools 72.0.0 removed support for deprecated setup.py test command:

https://setuptools.pypa.io/en/stable/history.html#v72-0-0

The test command has been removed. Users relying on ‘setup.py test’ will need
to migrate to another test runner or pin setuptools before this version.

Please migrate from removed test command.