Update Grafana from 5.1.4 to 5.2.1

* http://docs.grafana.org/guides/whats-new-in-v5-2/
* https://github.com/grafana/grafana/releases/tag/v5.2.0
* https://github.com/grafana/grafana/releases/tag/v5.2.1

addons/grafana/deployment.yaml

@@ -21,7 +21,7 @@ spec:
     spec:
       containers:
         - name: grafana
-          image: grafana/grafana:5.1.4
+          image: grafana/grafana:5.2.1
           env:
             - name: GF_SERVER_HTTP_PORT
               value: "8080"