Add a test case for DB schema comparison
Add a test case for DB schema comparison

Add a test case that allows to check if the DB schema obtained
by applying of migration scripts is equal to the one produced
from models definitions on MySQL and PostgreSQL.

Change-Id: I58e2cffd03396223c530d492cd18927c357b90e8

ionutbalutoiu/ironic,openstack/ironic,Tan0/ironic,SauloAislan/ironic,dims/ironic,ramineni/myironic,dims/ironic,naterh/ironic,SauloAislan/ironic,supermari0/ironic,faizan-barmawer/openstack_ironic,NaohiroTamura/ironic,openstack/ironic,naototty/vagrant-lxc-ironic,pshchelo/ironic,ionutbalutoiu/ironic,rackerlabs/ironic,NaohiroTamura/ironic,pshchelo/ironic,devananda/ironic,bacaldwell/ironic,debayanray/ironic_backup,redhat-openstack/ironic,froyobin/ironic,rdo-management/ironic,bacaldwell/ironic,hpproliant/ironic,Tehsmash/ironic,naototty/vagrant-lxc-ironic