FBR: upgrade oz on builders
To deal with the cloud image issue I was originally going to resolve
it slightly differently, I've not dealt with it in oz. the current
"Fedora version" that pungi specifies (F-22) now retains BIOS by
default, to use UEFI you can specify F-30 and if edk2 is available it
will use that by default.
So I'd like to upgrade the builders to oz-0.17.0-0.2.fc29