protected function registerCommands()
    {
        $this->app->singleton('revisions.migration', function ($app) {
            return new RevisionsTableCommand($app['files'], $app['composer']);
        });
        $this->app->singleton('revisions.upgrade5_3', function ($app) {
            return new RevisionsUpgradeCommand($app['files'], $app['composer']);
        });

        $this->commands([
            'revisions.migration',
            'revisions.upgrade5_3',
        ]);
    }