docs: remove file header with license reference

Author: DannyvdSluijs

tests/Drafts/Draft3Test.php

@@ -1,12 +1,5 @@
 <?php
 
-/*
- * This file is part of the JsonSchema package.
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
 namespace JsonSchema\Tests\Drafts;
 
 use JsonSchema\Constraints\Factory;