add k8s dashboard svc name and namespace (#83)

charts/kubernetes-dashboard/latest/questions.yml

 rancher_version: v2.0.7
 categories:
 - dashboard
+namespace: kube-system
 questions:
 - variable: defaultImage
   default: true

charts/kubernetes-dashboard/latest/templates/svc.yaml

@@ -18,7 +18,8 @@ metadata:
 spec:
   type: {{ .Values.service.type }}
   ports:
-  - port: {{ .Values.service.externalPort }}
+  - name: https
+    port: {{ .Values.service.externalPort }}
     targetPort: https
 {{- if .Values.service.nodePort }}
     nodePort: {{ .Values.service.nodePort }}