Remove use of deprecated 'setup.py test'
Since setuptools v41.5.0 (27 Oct 2019), the 'test' command is formally
deprecated and should not be used.
The pytest-runner package also lists itself as deprecated:
https://github.com/pytest-dev/pytest-runner
> Deprecation Notice
>
> pytest-runner depends on deprecated features of setuptools and relies
> on features that break security mechanisms in pip. For example
> 'setup_requires' and 'tests_require' bypass pip --require-hashes. See
> also pypa/setuptools#1684.
3 files changed
