Fixed deprecation warnings, flake8 of code and added python and django's to travis

[GitRon]

• Fixed django 4.0 deprecation warnings
• flake8 of code
• added python 3.5, 3.6 and 3.8 to travis
• added django 3.1 to travis
• created a travis matrix so all valid combinations are being tested
• added some tags to the README

[GitRon]

Hi @dmpayton

I fixed the deprecations and did some more stuff but the tests seems to fail now even though I didn't change anything at these points. Do you know if it was maybe broken before?

Thanks! Ronny

[GitRon]

Btw, I extended the travis matrix so we get proper check for all the relevant pyhton and django combinations.

[9mido]

Awesome work @GitRon ! Would you also be able to make a PR for issue 62? That way, the newest version for django 3 compatibility will get pushed to PyPi along with your PR.

[GitRon]

@9mido quite busy at the moment but I'll see what I can do

[GitRon]

@9mido I put this idea into a PR. Happy? :)

[9mido]

@GitRon Yes you rock! Woohoo!

Just wondering though the checks for it look like they have failed. Any ideas how to fix those?

I feel really dumb the PR you made looks very simple lol.

[GitRon]

@dmpayton @9mido Pipeline is fixed and PR is ready to merge.

[GitRon]

@dmpayton @9mido Would be awesome if somebody could review and merge it 😃

[blag]

Hi, I have forked this project, included a few PRs (including this one), and released a package to PyPI. You might have better luck with my fork.