Add support for django 4.0

[kernicPanel]

Django 4.0 introduces changes on middlewares, and signals. https://docs.djangoproject.com/en/4.0/releases/4.0/

The get_response argument for django.utils.deprecation.MiddlewareMixin.init() is required and doesn’t accept None.

The providing_args argument for django.dispatch.Signal is removed.

[leplatrem]

@kernicPanel Could you try to rebase your PR on latest master?

[kernicPanel]

@leplatrem I rebased this PR.

[codecov-commenter]

Codecov Report

Merging #62 (d682815) into main (7257535) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #62   +/-   ##
=======================================
  Coverage   97.81%   97.81%           
=======================================
  Files          19       19           
  Lines         594      594           
  Branches       93       93           
=======================================
  Hits          581      581           
  Misses          9        9           
  Partials        4        4           

Impacted Files	Coverage Δ
src/dockerflow/django/middleware.py	100.00% <100.00%> (ø)
src/dockerflow/django/signals.py	100.00% <100.00%> (ø)

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[leplatrem]

Thanks, apparently that wasn't enough to make the tests pass :(

[diox]

That's because you're trying to build Django 4.0 support on Python 3.6/3.7. Django 4.0 requires Python 3.8 or greater. In addition, there is also a failure for py38-lint:
src/dockerflow/django/middleware.py:42:52: BLK100 Black would make changes.

[kernicPanel]

Thanks for pointing this out, @diox
As I'm not familiar with tox, I hope this would pass now.

[diox]

Looks good, thanks for taking this on, @kernicPanel !

[kernicPanel]

Thanks for your support @diox and @leplatrem , I'm glad to have contributed!