Add new 'storage': {'production_ready': True} capability

This capability is needed to be used in the Tempest tests
to have the difference between Icehouse version (where tests
won't pass due to *really* huge running time) and new Juno
version, where this performance issue has been fixed.

Change-Id: I83bf184a58bfba0e48e09a754237a8b0a4dceb25
Merge "Add new 'storage': {'production_ready': True} capability"