Add filters to maxctrl show service

The filters were not listed.

maxctrl/lib/show.js

@@ -122,6 +122,11 @@ const service_fields = [
         path: 'relationships.servers.data[].id',
         description: 'Servers that the service uses'
     },
+    {
+        name: 'Filters',
+        path: 'relationships.filters.data[].id',
+        description: 'Filters that the service uses'
+    },
     {
         name: 'Parameters',
         path: 'attributes.parameters',