Fix whitespace

Author: franzliedke

src/Response/EmptyResponse.php

@@ -28,7 +28,7 @@ public function __construct($status = 204, array $headers = [])
         $body = new Stream('php://temp', 'r');
         parent::__construct($body, $status, $headers);
     }
-    
+
     /**
      * Create an empty response with the given headers.
      *

test/Response/EmptyResponseTest.php

@@ -21,7 +21,7 @@ public function testConstructor()
         $this->assertEquals('', (string) $response->getBody());
         $this->assertEquals(201, $response->getStatusCode());
     }
-    
+
     public function testHeaderConstructor()
     {
         $response = EmptyResponse::withHeaders(['x-empty' => ['true']]);