Skip ebs scenario test due to bug 1489581
Skip ebs scenario test due to bug 1489581

test_create_ebs_image_and_check_boot race fails frequently in
the cells and ceph jobs, so we need to skip it for now until
people can dig into what the failures are.

Change-Id: Id077a68a9cd274e5b68a36c8eb1032632ceaedc5
Related-Bug: #1489581

Juniper/tempest,izadorozhna/tempest,dkalashnik/tempest,bigswitch/tempest,sebrandon1/tempest,rakeshmi/tempest,vedujoshi/tempest,tonyli71/tempest,flyingfish007/tempest,cisco-openstack/tempest,rakeshmi/tempest,bigswitch/tempest,pczerkas/tempest,openstack/tempest,zsoltdudas/lis-tempest,LIS/lis-tempest,Tesora/tesora-tempest,flyingfish007/tempest,vedujoshi/tempest,LIS/lis-tempest,izadorozhna/tempest,sebrandon1/tempest,xbezdick/tempest,dkalashnik/tempest,cisco-openstack/tempest,masayukig/tempest,tonyli71/tempest,Juniper/tempest,zsoltdudas/lis-tempest,pczerkas/tempest,xbezdick/tempest,openstack/tempest,Tesora/tesora-tempest,masayukig/tempest