Gate: Use defaults from within roles

This PS uses the defaults contained within the roles used in the
gate.

Depends-On: I5ad1b593a711ffe353b012394d54044dede0691d
Change-Id: I52730474cefb917a23b679f4ff0703afd2b44989

tools/gate/playbooks/vars.yaml

@@ -12,53 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version:
+null: null
-  kubernetes: v1.10.2
-  helm: v2.8.2
-  cni: v0.6.0
-
-proxy:
-  http: null
-  https: null
-  noproxy: null
-
-images:
-  kubernetes:
-    kubeadm_aio: openstackhelm/kubeadm-aio:dev
-
-
-kubernetes:
-  network:
-    default_device: null
-  cluster:
-    cni: calico
-    pod_subnet: 192.168.0.0/16
-    domain: cluster.local
-
-nodes:
-  labels:
-    primary:
-      - name: openstack-helm-node-class
-        value: primary
-    nodes:
-      - name: openstack-helm-node-class
-        value: general
-    all:
-      - name: openstack-control-plane
-        value: enabled
-      - name: openstack-compute-node
-        value: enabled
-      - name: openvswitch
-        value: enabled
-      - name: linuxbridge
-        value: enabled
-      - name: ceph-mon
-        value: enabled
-      - name: ceph-osd
-        value: enabled
-      - name: ceph-mds
-        value: enabled
-      - name: ceph-rgw
-        value: enabled
-      - name: ceph-mgr
-        value: enabled