Warning labels don't conform to flake8 rules

[vpoulailleau]

Description

Warning labels don't conform to flake8 rules

Steps to Reproduce

1. Install a recent flake8
2. Install latest flake8-slots
3. Run flake8 --version

Actual result:

There was a critical error during execution of Flake8:
plugin code for `flake8-slots[SLOT]` does not match ^[A-Z]{1,3}[0-9]{0,3}$

Expected result:

Reproduces how often:

Version

• Operating System:
• Python:
• flake8-slots:

Installation source

Other Additional Information:

I think this comes from https://flake8.pycqa.org/en/latest/release-notes/5.0.0.html#backwards-incompatible-changes

[nkukard]

Still seems to be an issue with 0.1.6, release on GitHub is also only at 0.1.5