Add 3.4.0 version for upgrades.
Upgrade task to remove unused storage tables - EUCA-6462

EUCA-6462
State transitions now serial where necessary - EUCA-6479

Removal of a service from the enabled set is now performed serially with
a status check. Ensured submitted transitions use queues as per the
serialized states. Removed DISABLED from serialized states.

EUCA-6479
Merge remote-tracking branch 'origin/dev/sjones/EUCA-6462' into testing
Merge remote-tracking branch 'origin/dev/sjones/EUCA-6479' into testing