pylint license

[Joshua Root]

Looks like it's actually GPL-2+, not GPL-2. This is an important
distinction when there are dependencies or dependents that use a license
like Apache-2 or GPL-3+ that conflicts with GPL-2.

Unfortunately, with (L)GPL'd software the COPYING file usually just
contains one acceptable license version, and does not give any
information about whether later versions are allowed or not. If you're
lucky it will be mentioned somewhere in the docs, but if not, you have
to go to the license headers in the source files.

- Josh