cs: Switch to a stricter way of coding - this might break in a lot of places.

src/Bundle/ChillDocGeneratorBundle/Serializer/Normalizer/DocGenObjectNormalizer.php

@@ -7,6 +7,15 @@
  * the LICENSE file that was distributed with this source code.
  */
 
+declare(strict_types=1);
+
+/**
+ * Chill is a software for social workers.
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
 namespace Chill\DocGeneratorBundle\Serializer\Normalizer;
 
 use Chill\DocGeneratorBundle\Serializer\Helper\NormalizeNullValueHelper;