add support for extensions

manifests/main/config.pp

@@ -10,5 +10,8 @@ class postgresql_cd::main::config (
 
   if $fqdn == $pl_server_fqdn {
     include postgresql_cd::server::service
+    if $pl_use_exporter == true {
+      include postgresql_cd::exporter::service
+    }
   }
 }