prci: bump fedora release
Fedora 31 is the latest release, Fedora 30 is now the previous release.
New template boxes were built for current tests definitions with
updated dependencies.
Boxes were generated after https://github.com/freeipa/freeipa-pr-ci/pull/321
Signed-off-by: Armando Neto <abiagion@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>