upgrade coredns

Story: 2009874

Change-Id: Ibaa3b150e024918b6fc963eb6ca62bd18690a3c4
(cherry picked from commit 15c2bc2)
(cherry picked from commit bf7fd64)
(cherry picked from commit d7a502e)
(cherry picked from commit eaaa762)
(cherry picked from commit abc814f)
(cherry picked from commit a7a698c)

Author: GregWhiteyBialas

magnum/drivers/common/templates/kubernetes/fragments/core-dns-service.sh

@@ -74,8 +74,11 @@ data:
   Corefile: |
     .:53 {
         errors
-        log
-        health
+        log stdout
+        health {
+            lameduck 5s
+        }
+        ready
         kubernetes ${DNS_CLUSTER_DOMAIN} ${PORTAL_NETWORK_CIDR} ${PODS_NETWORK_CIDR} {
            pods verified
            fallthrough in-addr.arpa ip6.arpa

magnum/drivers/k8s_fedora_coreos_v1/templates/kubecluster.yaml

@@ -496,7 +496,7 @@ parameters:
   coredns_tag:
     type: string
     description: tag for coredns
-    default: 1.6.6
+    default: 1.8.7
 
   flannel_tag:
     type: string