Use database for non-zookeeper commands
Use database for non-zookeeper commands

Because we are in the process of migrating nodepool to zookeeper, we
no longer need database access for some CLI commands (eg: image-list).

Change-Id: I671caf1cad632295c0567a7a02053934ea97b151
Signed-off-by: Paul Belanger <e7139c8e6c4ea75cc1c287ce081b2dc0f3ab39ec@redhat.com>

Tesora/tesora-nodepool,Tesora/tesora-nodepool