Define stable/train job in stackviz
Define stable/train job in stackviz

Tempest is removing the stable/train job which
is used in stackviz gate
- https://review.opendev.org/c/openstack/tempest/+/822055

let's define the train job in-tree itself.

Change-Id: I23f8d4f08ebbf500dec21c80af41304c81fababf

openstack/stackviz,openstack/stackviz,openstack/stackviz