Added Validator and Gate facades for Lumen.

src/Generator.php

@@ -265,7 +265,8 @@ class Generator
           'Schema' => 'Illuminate\Support\Facades\Schema',
           'Session' => 'Illuminate\Support\Facades\Session',
           'Storage' => 'Illuminate\Support\Facades\Storage',
-          //'Validator' => 'Illuminate\Support\Facades\Validator',
+          'Validator' => 'Illuminate\Support\Facades\Validator',
+          'Gate' => 'Illuminate\Support\Facades\Gate',
         ];
 
         $facades = array_merge($facades, $this->config->get('app.aliases', []));