public function store(Request $request)
 {
     $this->validate($request, ['title' => 'required|max:255', 'source' => 'required|max:255']);
     Video::create($request->only(['title', 'source', 'description']));
     $this->flasher->success('Video Added!', 'Content is king (or queen)!');
     return redirect('admin/videos');
 }