remove Router

tests/TestCase/Http/ResponseTest.php

@@ -22,7 +22,6 @@ use Cake\Http\CorsBuilder;
 use Cake\Http\Exception\NotFoundException;
 use Cake\Http\Response;
 use Cake\Http\ServerRequest;
-use Cake\Routing\Router;
 use Cake\TestSuite\TestCase;
 use Zend\Diactoros\Stream;