Install koji-hub package during tests
Install koji-hub package during tests

Previously, the package was not installed, instead an empty file was
created in the location where the 'kojihub' module was supposed to live.

The package is only available for python2 on Fedora <= 29 and python3 on
Fedora >= 30.

Signed-off-by: Adam Cmiel <1217f9865bd733d1bcad0d0d64be310272c5592c@redhat.com>

release-engineering/koji-containerbuild,release-engineering/koji-containerbuild