[BUGFIX] fixes no response being send on download #31 (#32)

Author: KreutzerCode

src/PDFMerger/PDFMerger.php

@@ -106,11 +106,12 @@ public function stream(){
      */
     public function download(){
         $output = $this->output();
-        return new Response($output, 200, [
+        $response = new Response($output, 200, [
             'Content-Type' => 'application/pdf',
             'Content-Disposition' =>  'attachment; filename="' . $this->fileName . '"',
             'Content-Length' => strlen($output),
         ]);
+        return $response->send();
     }
 
     /**