public function bootstrap(Application $app)
 {
     $this->app = $app;
     $this->fs = new Filesystem();
     $paths = [$app->exportPath(), $app->homePath(), $app->storagePath(), $app->databasePath(), $app->publicPath(), $app->configPath()];
     foreach ($paths as $path) {
         $this->ensureDirectory($path);
     }
     $storagePaths = ['app', 'framework', 'framework/cache', 'framework/views', 'framework/sessions', 'logs', $app->getSlug()];
     foreach ($storagePaths as $path) {
         $this->ensureDirectory(path_join($app->storagePath(), $path));
     }
 }