s390x buildbot upgraded (fedora 25 on z13)

[Mark Wielaard]

Hi all,

Thanks to Dan Horák the s390x buildbot has been migrated to a guest
on a z13 machine and upgraded to Fedora 25.
http://144.217.14.79/buildslaves/marist-fedora-s390x

Fedora release 25 (Twenty Five)
Linux 4.8.8-300.fc25.s390x
g++ 6.2.1
binutils 2.26.1

But I still haven't figured out why there are some consistent test
failures. But those seem to happen on all arches, not just s390x.

Cheers,

Mark