remove python setup.py test

remove python setup.py test

Removed the "python setup.py test" feature in favor of a straight run of
"tox".   Per Pypa / pytest developers, "setup.py" commands are in general
headed towards deprecation in favor of tox.  The tox.ini script has been
updated such that running "tox" with no arguments will perform a single run
of the test suite against the default installed Python interpreter.

.. seealso::

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

    https://github.com/pytest-dev/pytest/issues/5534

Change-Id: Ib92ef8d20ad0e6f1e1b9d25051b788788cc69b02
Fixes: #592