title: Yii2 Adding new console controller
body: <p>Why <code>yii2</code> throw exception, when I try use console controller? Code:</p>
  
  <pre><code>&lt;?php
  
  namespace app\commands;
  
  use yii\console\Controller;
  class Hashtag extends Controller
  {
  
  
      public function actionIndex($search = 'test')
      {
        echo $search;
      }
  }
  </code></pre>
  
  <p>Controller located in: app\commands\HashtagController
  When using terminal: <code>php yii hashtag</code></p>
  
  <pre><code>Exception 'yii\base\UnknownClassException' with message 'Unable to find 'app\commands\HashtagController' in file: /var/www/html/yiitask/yii2/commands/HashtagController.php. Namespace missing?'
  
  in /var/www/html/yiitask/yii2/vendor/yiisoft/yii2/BaseYii.php:291
  </code></pre>
  
  <p>Other controller in this folder that was created before, working well.</p>