There are missing repos for ovirt-3.6 and ovirt-4.0 on centos 7.4

[lukas-bednar]

I had to disable tests for 3.6 & 4.0 repositories because they started to fail on

    "msg": "Failure talking to yum: failure: repodata/repomd.xml from centos-ovirt40-release: [Errno 256] No more mirrors to try.\nhttp://mirror.centos.org/centos/7/virt/x86_64/ovirt-4.0/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found"

I disabled it as part of #153

This happened because CentOs7.4 was released ... and you can not find that 3.6 & 4.0 in latest link http://mirror.centos.org/centos/7/virt/x86_64/ you can still find 3.6 & 4.0 on CentOs 7.3 link http://mirror.centos.org/centos/7.3.1611/virt/x86_64/