As part of Ocata, nova has made the cell_v2 setup manditory for the
nova-api db sync process. This change adds a simple cell_v2 setup with a
cell0 and an execution of the 'nova-manage cell_v2 simple_cell_setup' as
part of the nova-api db setup and sync process.
Change-Id: Idfc369e9e17f7d5a30ce4ff52beb604dd4a6ac23
Closes-Bug: #1649341