Now that Deckhand supports rolling back to revision 0 with
https://review.openstack.org/#/c/592725/ it is preferrable to
exercise this functionality instead of deleting all revisions
in Deckhand's database, so that previous revision history
isn't lost.
Deckhand is fast-forwarded to
0b5aa2e98a1ab5ab8a58c9dec3c1f88ef00d17a9 which contains
the commit required for SY to be able to make use of this
new change in Deckhand's client, as well as to align with
Promenade's Deckhand fast-forward of Deckhand in
https://review.openstack.org/#/c/604459/
Depends-On: https://review.openstack.org/#/c/592725/
Change-Id: Iebbfeb5e6c74b3e2f09b2137ec14482cc8fa4f44