[proposal] run tests only with supported django and python versions

[jairhenrique]

This test matrix proposal is based on https://endoflife.date/django

[codecov]

Codecov Report

Merging #110 (bd8a954) into master (8e941fe) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #110   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
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  Files           42        42           
  Lines         1209      1209           
=========================================
  Hits          1209      1209           

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[jrobichaud]

Since the beginning of the project I had this in mind:

1. keep the compatibility until there are breaking changes (Ex: threadlocal vs contextvars) or the maintainability is unbearable (Ex: I kept python 3.4 for a long time)
2. drop support with documented incompatibility in a notable release

Does that sound ok to you?

I am open to discussion.

[jairhenrique]

@jrobichaud makes senses, but why support libraries and versions of python who doesn't have support anymore?

I think removing support for these versions encourages and force the community to keep their environment up to date.