HEADS UP: pip upgraded from 9 to 18 (rawhide only)

[Miro Hrončok]

I've just built python-pip-18.0-1.fc29.

It has a lot of breaking changes, so please file bugs if you have 
problems. We do not plan to upgrade pip in stable Fedora releases.

Release notes: https://pip.pypa.io/en/stable/news/

See notes for 18 and 10, as we skipped 10.

Note that upstream changed version scheme, nothing existed between 10 
and 18.

Thanks,