TestCase attributes trigger N815

[jaap3]

With the recent release of pep-8-naming I suddenly get N815 warnings for the maxDiff attribute on unittest.TestCases (https://docs.python.org/3/library/unittest.html#unittest.TestCase.maxDiff)

I haven't verified this, but I assume other TestCase attributes will also trigger this (i.e.
failureException (https://docs.python.org/3/library/unittest.html#unittest.TestCase.failureException), longMessage (https://docs.python.org/3/library/unittest.html#unittest.TestCase.longMessage))

[jparise]

N815 (mixedCased variable names at class scope) and N816 (mixedCased variable names at global scope) are new error codes in the 0.8.0 release. You can disable them to get the previous pep8-naming behavior.

I agree that they're pretty noisy on a code base that uses unittest. I think we should ignore those well-known stdlib symbols by default, perhaps by extending and honoring the ignore-names list when checking for N815/N816. (Currently, ignore-names is only used by N802 errors.)

@5j9, you introduced these new errors. What do you think?

[jparise]

#43 is somewhat related, too.

[jaap3]

Thanks for the quick fixes 👍