The 2.2.0 and 2.2.1 versions broke poetry and no fix is in sight.

python-poetry#1

Remove all strict dependency version bounds.
Remove unnecessary curly braces.

Bump to prerelease version because upstream poetry released 1.2.0 with a cleo
>= 1.0.0a5 dependency (https://github.com/python-poetry/poetry/issues/6353) and
cleo likely will not see a stable release before poetry 1.3.0 is out
(https://github.com/python-poetry/cleo/issues/246).
As the likelyhood of running into instabilities due to other poetry
dependencies when downgrading to poetry < 1.2.0 is higher than when upgrading
only cleo to an unstable version, upgrading cleo to an unstable version is the
lesser of the two evils.

Update upstream url.
Remove unnecessary quotes.
Switch to PEP517.

We cannot update cleo except in tandem with poetry.

I tried to package is actually too new for poetry, so we need an old one. I
escaped needing to add an epoch by a hair, because I didn't db-update this yet.
DON'T LOOK AT ME LIKE THAT IT'S FINE.

needed for python-poetry