add notification facade

config/app.php

@@ -208,6 +208,7 @@
         'Lang' => Illuminate\Support\Facades\Lang::class,
         'Log' => Illuminate\Support\Facades\Log::class,
         'Mail' => Illuminate\Support\Facades\Mail::class,
+        'Notification' => Illuminate\Support\Facades\Notification::class,
         'Password' => Illuminate\Support\Facades\Password::class,
         'Queue' => Illuminate\Support\Facades\Queue::class,
         'Redirect' => Illuminate\Support\Facades\Redirect::class,