Fix helm upgrade on grafana helm chart (#3373)

* Update job.yaml

Without those annotation, helm upgrade fails because of :
https://github.com/kubernetes/helm/issues/1769

* Increasing version number

stable/grafana/Chart.yaml

@@ -1,5 +1,5 @@
 name: grafana
-version: 0.5.7
+version: 0.5.8
 description: The leading tool for querying and visualizing time series and metrics.
 home: https://grafana.net
 icon: https://raw.githubusercontent.com/grafana/grafana/master/public/img/logo_transparent_400x.png

stable/grafana/templates/job.yaml

@@ -2,6 +2,10 @@
 apiVersion: batch/v1
 kind: Job
 metadata:
+  annotations:
+    "helm.sh/hook": post-install
+    "helm.sh/hook-weight": "-5"
+    "helm.sh/hook-delete-policy": hook-succeeded
   labels:
     app: {{ template "grafana.fullname" . }}
     chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"