Cut over to grizzly -> havana

* change BASE_RELEASE and TARGET_RELEASE in grenaderc
* remove work-arounds from devstack.localrc.target
* remove upgrade steps from the upgrade-* scripts
* change references to release names in variables to BASE_ and TARGET_
* remove Javelin check from check-sanity, will return in verify-javelin
  in https://review.openstack.org/#/c/26257/

Fixes bug 1175340

Change-Id: If1523c73ebefeaf3d3e3efdfbc053f47365d123a
Add verify-javelin

* Verify the Javelin data created before the upgrade process
* Remove Javelin resources to make room for exercises

Change-Id: I5cf8ae0b9a1ab78186a55d7a428ae44f9f98d2ad
Merge branch 'havana' into dt-test
Merge branch 'verify-javelin' into dt-test