Revert "Revert "Specify cell0 db creation""
Revert "Revert "Specify cell0 db creation""

This reverts commit 34f3ab689616517888422582357d0d4a38e0925d.

Creating the cells database doesn't hurt anything and will fix
issues using the new Docker nova services for development
(these packages are more recent and require cells).

Change-Id: I85b0e80ca208ef3ca3dfadfe6e98d83ec009a31d

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates