poetry: Switch from using pipenv to poetry

[dkoston]

This should be a seamless switch to using poetry for you. I assume you were using twine for https reasons when publishing? Poetry has you covered there but can still use twine if you want to.

You'll need to export PYPI_TOKEN and PYPI_TEST_TOKEN and then run make configure_pypi_publishing to get publishing to pypi and test.pypi.org set up.

[manchenkoff]

Hey @dkoston, thanks for the contribution! Makefile was used mostly for the development environment, that's why I used native commands in the pipelines. I have this planned, but didn't have time for migration 😄 so, I assume it will close #32.

I will try to review this PR in the next couple of days!

By the way, there is some build error related to poetry, would appreciate it if you could take a look in the meantime 👍

[dkoston]

@manchenkoff no problem. I realized I used too old of a poetry version. Pushed fix. Will keep an eye on the build.

Have a PR coming that allows all IANA content types as well