Bump version to 3.3.0 for release

[blag]

Changes proposed in this PR:

• Bump version to 3.3.0 for release

Tips for an ideal PR

• You have read our Code of Conduct: https://github.com/pinax/.github/blob/master/CODE_OF_CONDUCT.md
• You have read our Contributing info: https://github.com/pinax/.github/blob/master/CONTRIBUTING.md
• The PR is atomic
• Unit tests have been updated/added, if needed
• App version number has been updated in setup.py (Pinax uses SemVer)
• Change Log has been updated
• You have added your name to the AUTHORS file

[blag]

No matter what configuration I tried, setuptools kept building a distribution with both account and tests packages in it. We shouldn't be including our tests package in our distribution.

So I tweaked the config to use Poetry to handle dependencies (poetry add/poetry remove/poetry lock), build the distribution (poetry build) and we can also use it to publish the distribution to PyPI (poetry publish).

Switching to a different package build system is a big change, so I'm happy to have a discussion about it.

[uhurusurfa]

I have no specific reasons to prefer setuptools over poetry but all the Pinax apps are all currently using setuptools and not sure if the Pinax rteam want to switch tools.
We probably will not get any communication with them as they seem to have abandoned the projects for the most part.
If you feel there is significant benefit to using Poetry I am up for it.

Did you look at this articlke to try to fix setuptools:
https://stackoverflow.com/questions/608855/excluding-a-top-level-directory-from-a-setuptools-package

[blag]

I figured out that setuptools wasn't my problem - it was MANIFEST.in. I'll close this and open a separate PR that readies this for version 3.3.0. It's much simpler.

I'd mildly prefer that we stick with what other Pinax projects use, but if we run into things we can't update (like their GHAs), I figure we can work around them and do what we want. However, now that I got things working with setuptools I think we stick with it for as long as it works for us.