setup.py: pip req versioning fix
setup.py: pip req versioning fix

Pip 10 is changed module structure with `pip.req`. Adding proper import
handling logic to the `setup.py` to install properly.

Signed-off-by: Gergő Nagy <1a73af9e7ae00182733b2292511b814be66f065f@gergonagy.com>

ngergo/ratatoskr