Validate roles data and network data
Validate roles data and network data

Adds workflow steps to validate the existence and validity of the
roles_data.yaml and network_data.yaml that is generated when the
plan is created/updated.

Change-Id: Ic02d1773d37b3d8e258b3160ac50ac3a9594166e
Implements: blueprint validate-roles-networks

openstack/tripleo-common,openstack/tripleo-common