Add script to keep kube-prometheus rules in sync with helm charts

Bump prometheus to 2.0.0, prometheus-operator to 0.15.0, alertmanager to 0.12.0 and node-exporter to 0.15.1, grafana to 4.6.3
migrate prometheus alerts to yaml notation

assets/prometheus/rules/kube-controller-manager.rules.yaml

@@ -10,4 +10,4 @@ groups:
       description: There is no running K8S controller manager. Deployments and replication
         controllers are not making progress.
       runbook: https://coreos.com/tectonic/docs/latest/troubleshooting/controller-recovery.html#recovering-a-controller-manager
-      summary: Controller manager is down
+      summary: Controller manager is down
\ No newline at end of file

hack/grafana-dashboards-configmap-generator/bin/grafana_dashboards_generate.sh

@@ -203,7 +203,7 @@ addArrayToConfigMap() {
     # Dashboard foot
     test "$type" = "dashboard" && cat $DASHBOARD_FOOT_FILE
   done
-  echo "---"
+  #echo "---"
 
   IFS=$OLDIFS
   return 0