[attrs] Support attr.s(eq=..., order=...)

[euresti]

attrs 19.2.0 added support for eq and order and deprecated to attr.s.
It also deprecated cmp.

Fixes #7615

[msullivan]

Looks good! Thanks.

[ilevkivskyi]

Can this cause false positives for people who have an older version of attrs? If yes, this is probably something we should mention in the release notes probably.

[euresti]

Yes this will cause false positives for older versions of attrs. I don't know what the process for that normally is.

[belm0]

Following up on PR comment 47093eb#r35428812

Failing on deprecated API use doesn't seem in line with mypy's scope, and defeats Python's tried and true depreciation mechanisms.

The timing of say, when a project is forced to upgrade attrs due to a transitive dependency and when it's able to migrate it's own code off a deprecated API is often different due to policy and other constraints. The runtime deprecation mechanism and supporting tools allows projects to deal with this sanely.

[euresti]

Yep. It's been fixed. #7675

[belm0]

@euresti

Yep. It's been fixed. #7675

Well, but unfortunately the fix didn't make it into the new 0.740 release 😿

foo.py:23: error: cmp is deprecated, use eq and order

please have it patched...