What needs to be done?

In order to make sure that all features of playground like:

• running code
• formatting code
• sharing code
• uploading datasets
• help

works as intended we need to implement truly functional tests.

More details: https://symfony.com/doc/current/testing/end_to_end.html

Website should get two new dependencies:

composer require --dev symfony/panther
composer require --dev dbrekelmans/bdi