Use DNF instead of YUM.

[FaramosCZ]

Yum is deprecated and since Fedora 30 it is removed entirely (its binary).

[FaramosCZ]

I could've pushed it without PR, however I'm not confident enough it won't break things.

Since Fedora 30 the /usr/bin/yum no longer exists.
And we can either use this patch, or set an alias at the beginning which would overwrite "yum" to "dnf".
By commenting this alias out, we would be able to run this tests on a systems without dnf too, even though they are not really suited for them.

I'd also like Jakub's opinion, since he's in charge of some tests automation which use those tests.

[praiskup]

As an alternative, we can use 'dnf-yum' package.

[hhorak]

Using dnf will make the scripts not work in RHEL-7 for example, so I'd rather go with 'dnf-yum' as @praiskup proposes. I guess installing it on Fedora only could work well.

[kubco2]

I am more for dnf-yum too.

[FaramosCZ]

'dnf-yum' can't be installed inside beaker :(
It conflicts with 'yum' on which beaker client depends

[praiskup]

@FaramosCZ that sounds like a bug either in dnf-yum or yum or snake or beaker client (that it depends on yum).

[praiskup]

I've reported this https://bugzilla.redhat.com/show_bug.cgi?id=1669061 (this seems to be problem only on Fedora 30 (rawhide)).