Add a tox configuration file for easier testing.
Review Request #11362 — Created Jan. 7, 2021 and submitted
This enables us to use tox to test the wide range of Python and Django
versions, as well as multiple databases, without having to manually run
each combination. A simple
toxcommand invocation will run the entire
test suite on all combinations. Tox will manage the creation of
virtualenvs for the tree and run the tests in each.
Been using this locally for much of Django Evolution 2.0 development and