Add --class-const-naming-style

[cdce8p]

Steps

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• Add a ChangeLog entry describing what your PR does.
• If it's a new feature or an important bug fix, add a What's New entry in doc/whatsnew/<current release.rst>.
• Write a good description on what the PR does.

Description

Add a new naming style class-const.
This will apply to:

• Enum constants
• Class variables if annotated with ClassVar

Although this technically is a new feature, there might be a point in including it in 2.7.3 (see issue below).

Type of Changes

	Type
✓	🐛 Bug fix
✓	✨ New feature
	🔨 Refactoring
✓	📜 Docs

Related Issue

Closes #4181

[coveralls]

Coverage increased (+0.001%) to 91.487% when pulling f844792 on cdce8p:naming-style-class_const into 803a252 on PyCQA:master.

[Pierre-Sassoulas]

Nice feature for 2.8 :)
Edit: Or it could be considered a fix for 2.7.3

[cdce8p]

A utils.is_class_var function does make a lot of sense. I updated the MR.

I would consider it a fix. The impact is most likely limited and can be easily mitigated by adding class-const-naming-style=any to the pylintrc file.

[cdce8p]

I believe this MR is ready for merging