Improve pytest setuptools integration

[ericpre]

Makes setup.py more consistent (see #2020) following [pytest good practices recommandation].(https://docs.pytest.org/en/latest/goodpractices.html#integrating-with-setuptools-python-setup-py-test-pytest-runner)

• add support for python setup.py test to run the test suite -see setuptools documentation,
• ready for review.

[francisco-dlp]

Would it be good to:

• Modify the Dev Guide to document this way of running the test
• Add the --mpl option?

[ericpre]

Adding --mpl should be possible but this feature will be deprecated soon, see pytest-dev/pytest#3523... but there may be alternative in the future. I put this on hold for now.

[dnjohnstone]

Is this still relevant?

[tjof2]

Agree with @dnjohnstone - @ericpre is this, and the related issue #2020, still relevant? Or can the issue and PR both be closed.

[tjof2]

Sorry @ericpre that was meant to be sent as a pull request, not a push...!

[ericpre]

In order to improve and simplify all these (testing, packaging, etc.), I suspect that it may be good looking at using pyproject.toml:

• https://snarky.ca/what-the-heck-is-pyproject-toml
• https://docs.pytest.org/en/latest/customize.html#pyproject-toml
• https://black.readthedocs.io/en/stable/pyproject_toml.html

[jlaehne]

Any update on this one? Should it be included in 1.6.2?

[ericpre]

I have left this one on hold, because I think that the build tool/configuration are still fluid at the moment... Closing it for now.