Bump docker to 1.13.1 for k8s clusters.

Change-Id: I72e2a0792b561b3a156543b7b782d4e62f863aec
diff --git a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
index a6869dd..85c2aed 100644
--- a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
+++ b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
@@ -20,7 +20,7 @@
     etcd_initial_token: IN7KaRMSo3xkGxkjAAPtkRkAgqN4ZNRq
 
     # docker package version
-    kubernetes_docker_package: docker-engine=1.12.6-0~ubuntu-xenial
+    kubernetes_docker_package: docker-engine=1.13.1-0~ubuntu-xenial
 
     # component docker images
     kubernetes_opencontrail_cni_image: docker-prod-virtual.docker.mirantis.net/mirantis/kubernetes/contrail-integration/contrail-cni:v1.0.0