Rename project to tox-poetry-helpers

[sinoroc]

The name for the plugin might not be fitting anymore. A more general name such as tox-poetry-helpers might be a better fit.

[johnthagen]

It's too bad tox-poetry is already taken.

Another idea could be tox-poetry-dependencies (drop the dev) to make it a little more inclusive.

Or even tox-poetry-plugin?

[sinoroc]

Overly specific name, indeed! It was meant to go no further than a proof concept to address this issue: python-poetry/poetry#1745
Now it has a different shape than initially planned. I guess, once the plugin and its implementation show enough usefulness and reliability we can rename everything.