invalid-module-name (N999) should not apply to non-*.py files

[andersk]

A script that isn’t named *.py (example) must be intended to be invoked from the command line, not imported as a module. So it doesn’t matter if its name is an invalid module name, and we should not emit

scripts/restart-server:1:1: N999 Invalid module name: 'restart-server'

Cc @sbrugman (#2855)

By the way, although we document this rule as being from pep8-naming, it isn’t; it’s from flake8-module-name.

[charliermarsh]

Thanks. I can fix this real quick.