Automate counting of live services and orgs

Returns the data calculated by the API. Stored in Redis against a
hardcoded key so that no-one hammering the home page is directly hitting
the database.

app/notify_client/service_api_client.py

@@ -98,6 +98,14 @@ class ServiceAPIClient(NotifyAdminAPIClient):
         endpoint = "/service/{0}".format(service_id)
         return self.post(endpoint, data)
 
+    @cache.delete('live-service-and-organisation-counts')
+    def update_status(self, service_id, live):
+        return self.update_service(
+            service_id,
+            message_limit=250000 if live else 50,
+            restricted=(not live),
+        )
+
     # This method is not cached because it calls through to one which is
     def update_service_with_properties(self, service_id, properties):
         return self.update_service(service_id, **properties)