Allow override of service type for zuul-web

To attach a service to a GCE loadbalancer, the service must be a
NodePort not a ClusterIP.  Allow users to specify that as an
option.  ClusterIP is the default.

Change-Id: I98a31f14c110293ac66d3a356accdf1e925663e5

charts/zuul/templates/web/service.yaml

@@ -8,7 +8,7 @@ metadata:
   labels:
 {{- include "zuul.web.labels" . | indent 4 }}
 spec:
-  type: ClusterIP
+  type: {{ .Values.web.serviceType }}
   ports:
   - name: zuul-web
     port: {{ .Values.web.port }}

charts/zuul/values.yaml

@@ -20,6 +20,7 @@ web:
   enabled: true
   replicas: 3
   port: 9000
+  serviceType: ClusterIP
 
 ingress:
   enabled: false