During Laravel migration at T1484, per https://laravel.com/docs/5.4/upgrade, we've installed the laravel/browser-kit-testing package.
Tests can be migrated to the new, simpler HTTP tests interface, following the doc at https://laravel.com/docs/5.4/http-tests (or a more recent version of this doc).
An other option to consider is to use Laravel Dusk, https://laravel.com/docs/5.4/dusk