Add build-system requirements and isort configuration to pyproject.toml

[mwtoews]

This implements PEP 517 and PEP 518 to describe the build-system requirements in pyproject.toml.

Other things in this PR:

• Move isort configuration to pyproject.toml, so these don't need to be repeated when invoking the command
• When building packages, use python -m build instead of directly invoking setup.py (see Why you shouldn't invoke setup.py directly)
• Add twine check to see if source and wheel packages are good before uploading to PyPI
• Remove MANIFEST and add it to .gitignore

[konstantinstadler]

This sounds interesting. Would that change the workflow for building/uploading to pypi, or building the conda-forge?

[coveralls]

Coverage: 97.03%. Remained the same when pulling 2b04af13b091b7aaecc56043b98838ab2a3d6a8a on mwtoews:pyproject-toml into fdd1087c1b6ccfde22608f7234bf8e1304a9a0a5 on konstantinstadler:master.

[konstantinstadler]

Also, it requires the build package, so this probably should go into the environment.yml file?

[mwtoews]

This simplifies the workflow for build/upload for PyPI since you don't need to install the build-time dependencies (often setuptools and wheel), as this is done in this PR by build. Both sdist and wheels are built and uploaded to PyPI. And no, build should not be added to environment.yml, since it is not a run-time dependency.

I don't believe anything else needs to be done with https://github.com/conda-forge/country_converter-feedstock/blob/main/recipe/meta.yaml

[konstantinstadler]

Mmmh, but where does build gets installed in your pull request?

Do the changes in pyproject some magic? Generally, we have the environment.yml as a development environment (it also contains isort, pytest and such things).

[mwtoews]

build is installed in this PR here: https://github.com/konstantinstadler/country_converter/blob/2b04af13b091b7aaecc56043b98838ab2a3d6a8a/.github/workflows/publish_pypi.yml#L32 (along with twine to check the packages before they are uploaded).

But I still don't think build should be added to environment.yml, since it is not a runtime or development dependency (pytest, isort, etc.). Or at least I haven't seen it appear as a dependency with other projects. Typically, it's just pip install build followed by python -m build in a CI workflow used for building and publishing.

Also, I should note that when someone does pip install country_converter with the current versions of pip, it shows a warning messsage:

DEPRECATION: country_converter is being installed using the legacy 'setup.py install' method, because it does not have a 'pyproject.toml' and the 'wheel' package is not installed. pip 23.1 will enforce this behaviour change. A possible replacement is to enable the '--use-pep517' option. Discussion can be found at https://github.com/pypa/pip/issues/8559

This PR will obviously resolve the warning.

[konstantinstadler]

Fantastic - thanks for the follow up (sorry, overlooked the pip install in the workflow).