aufn/ceph: Change default storage capacities

Author: assumptionsandg

etc/kayobe/environments/aufn-ceph/tenks.yml

@@ -21,7 +21,7 @@ node_types:
     volumes:
       # There is a minimum disk space capacity requirement of 4GiB when using Ironic Python Agent:
       # https://github.com/openstack/ironic-python-agent/blob/master/ironic_python_agent/utils.py#L290
-      - capacity: 20GiB
+      - capacity: 15GiB
       # Ceph volume
       - capacity: 20GiB
     physical_networks:
@@ -34,7 +34,7 @@ node_types:
     volumes:
       # There is a minimum disk space capacity requirement of 4GiB when using Ironic Python Agent:
       # https://github.com/openstack/ironic-python-agent/blob/master/ironic_python_agent/utils.py#L290
-      - capacity: 20GiB
+      - capacity: 15GiB
     physical_networks:
       - provision-net
       - cloud-net