Revert "Temporarily stop running tripleo seed/undercloud"

This reverts commit 794b1d4e89e5d38de729f362334830706ba08c09.

The new pipeline makes running these jobs again feasible.

Change-Id: I6ebed8a5003424e5ac34cc08ca4dd93230175a1a
Merge "Revert "Temporarily stop running tripleo seed/undercloud""