Open Stack

I've reverted the devstack change from 4/29 that uses fernet tokens by 
default [1]. This was the cause of the top non-infra-related CI failure 
since it landed about 3 weeks ago. There are some patches up from Lance 
Bragstad and Adam Young in Keystone to try and fix it, but until those 
make better progress we need to revert the change to get things flowing 
again.

[1] https://review.openstack.org/#/c/318116/

-- 

Thanks,

Matt Riedemann