laravel-api-tester hang up if response status code 204

``` php
class SomeController
{
    public function test()
    {
        return response('', 204);

        // or with dingo response helper
        // return $this->response->noContent();
    }
}

Route::get('test', 'SomeController@test');
```

Postman works properly when get to /test, but laravel-api-tester hang up.
