The "flake8 --version" switch could report the underlying Python version
Since Flake8 supports both Python2 and Python3, we should provide the information about which version of Python is used by the checker.
This has some importance for the AST based checkers (pyflakes and mccabe) because the Python 3 code is reported as invalid if flake8 uses Python 2 (and the reverse is true).
pep8 tool does not suffer this issue because it breaks the source code into tokens, and erase the differences.
The proposal is to extend the output of
flake8 --version with the Python version.