Allow platformdirs 3.x (fix #719)

[musicinmybrain]

Purpose

This PR expands the allowed versions of the platformdirs dependency from 2.x only to 2.x or 3.x. This would fix #719 and is required downstream in Fedora Linux for compatibility with the current version of platformdirs.

Approach

The upper version bound in setup.cfg is trivially adjusted.

Open Questions and Pre-Merge TODOs

[x] Ran tox locally with no regressions

Resources & Links

The sole breaking change in the changelog for platformdirs 3.0.0 is:

• BREAKING Changed the config directory on macOS to point to */Library/Application Support

[abravalheri]

Thank you very much for the contribution @musicinmybrain.

The sole breaking change in the changelog for platformdirs 3.0.0 is:
BREAKING Changed the config directory on macOS to point to */Library/Application Support

This might mean that existing configuration files for PyScaffold in macOS will stop working because they will no longer be in the right place, right?

---

On a unrelated note, @FlorianWilhelm, it seems that the tests started failing recently on macOS with a weird error message: locale.Error: unsupported locale setting.

It seems that this is related to a recent change in sphinx: #717 (comment). Do you have any idea on how to deal with that?

[abravalheri]

I added automatic migration to ensure backward compatibility.

[coveralls]

coverage: 97.798% (+0.02%) from 97.78% when pulling 3a30c92 on musicinmybrain:platformdirs3 into ee97593 on pyscaffold:master.

[musicinmybrain]

I added automatic migration to ensure backward compatibility.

Thanks!