Support alternate tox.ini locations.

[jsirois]

No description provided.

[jsirois]

This is being used successfully in this branch: pex-tool/pex#2198

[jsirois]

Thanks for the review @cognifloyd. I think maybe the general Pants community thinks merging someone else's PR is OK, and in this case it was, but, in general, this seems very much not cool to do. I know I often have later thoughts and make adjustments before landing.

[cognifloyd]

@jsirois if you are actively working on a PR then you must include WIP in the title, or mark it as draft (a core GitHub feature). Once it is out of draft, then any maintainer can and SHOULD merge to avoid PRs piling up.

I have been a mere contributor (not a maintainer) on many projects where my PR sat approved but unmerged for months because the maintainers were used to the closed source practice of PR authors merging their own PR. In open source projects, the last maintainer that approves is responsible for merging to ensure that doesn't happen.

[jsirois]

Ok, I hate that idea (for maintainers, makes sense for merging non maintainer PRs of course!). But at least I know your reasoning.