Fix typo for "directory" to "Directory" in volume mounts (#1236)

* Fix typo of directory to DIrectory

https://kubernetes.io/docs/concepts/storage/volumes/
`apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: k8s.gcr.io/test-webserver
    name: test-container
    volumeMounts:
    - mountPath: /test-pd
      name: test-volume
  volumes:
  - name: test-volume
    hostPath:
      # directory location on host
      path: /data
      # this field is optional
      type: Directory
`

Tried to deploy with the mountGrafanaConfig and got an error saying "directory" not supported

* Increment version

* Increment version

* Change version for grafana

helm/grafana/Chart.yaml

@@ -8,4 +8,4 @@ maintainers:
 name: grafana
 sources:
 - https://github.com/coreos/prometheus-operator
-version: 0.0.26
+version: 0.0.27

helm/grafana/templates/grafana-deployment.yaml

@@ -121,7 +121,7 @@ spec:
         - name: grafana-config
           hostPath:
             path: /etc/grafana
-            type: directory
+            type: Directory
       {{- end }}
       {{- range .Values.serverDashboardConfigmaps }}
         - name: {{ . }}

helm/kube-prometheus/Chart.yaml

@@ -9,4 +9,4 @@ maintainers:
 name: kube-prometheus
 sources:
   - https://github.com/coreos/prometheus-operator
-version: 0.0.51
+version: 0.0.52

helm/kube-prometheus/requirements.yaml

@@ -59,7 +59,7 @@ dependencies:
     condition: deployExporterNode
 
   - name: grafana
-    version: 0.0.26
+    version: 0.0.27
     #e2e-repository: file://../grafana
     repository: https://s3-eu-west-1.amazonaws.com/coreos-charts/stable/
     condition: deployGrafana