Adding support for canal network plugin

This patch provides support for Canal network plugin installation
as a self-hosted app, see the following link for details:

https://github.com/tigera/canal/tree/master/k8s-install

roles/kubernetes/node/templates/cni-canal.conf.j2

@@ -0,0 +1,17 @@
+{
+  "name": "canal-k8s-network",
+  "type": "flannel",
+  "delegate": {
+    "type": "calico",
+    "etcd_endpoints": "{{ etcd_access_endpoint }}",
+    "log_level": "info",
+    {% if enable_network_policy is defined and enable_network_policy == True %}
+      "policy": {
+        "type": "k8s"
+      },
+    {% endif %}
+    "kubernetes": {
+      "kubeconfig": "{{ kube_config_dir }}/node-kubeconfig.yaml"
+    }
+  }
+}