allow and/or document how to run a single test

[cjerdonek]

I could be doing something wrong, but I wasn't able to run a single test using tox.

After searching online, when I changed a line in tox.ini to be the following, I was able to do it:

python -m unittest {posargs}

Was I missing something to be able to do this without altering tox.ini?

[aaugustin]

I don't think you missed anything.

Feel free to commit that change!

[aaugustin]

(I usually run isolated tests with python -m unittest .... I never tried tox ....)

[cjerdonek]

That's a good point. I might have done that in the past but since forgot.

Do you have thoughts on where to put tips on how to run tests for now? A code comment in the tox.ini file? I don't think there's a contributing file yet.

[aaugustin]

There's docs/contributing.rst, which could use some details...