Add missing polishsymfonycommunity/symfony-mocker-container dependency

[jakubtobiasz]

Sylius 1.10.6 release has broken running the app based on the Sylius-Standard in a test environment. It's caused by moving "polishsymfonycommunity/symfony-mocker-container" to require-dev. polishsymfonycommunity/symfony-mocker-container is no longer being downloaded so it throws error because in test env it is used in src/Kernel.php.

[lchrusciel]

Hey Jakub, thanks a lot for your contribution.

If I see correctly, the PR is failing due to this class: https://github.com/Sylius/Sylius/blob/master/src/Sylius/Bundle/ApiBundle/EventSubscriber/KernelRequestEventSubscriber.php

Can you debug it and fix the build? I assume, that following this upgrade: https://github.com/Sylius/Sylius/blob/master/UPGRADE-API-1.10.md#upgrade-from-v1100-to-v1101 should do the trick

[jakubtobiasz]

@lchrusciel I've enabled Sylius API in services_test.yaml. I think it's the best place because we achieve passed tests along with Sylius API disabled by default in an app.

I've run all tests on my fork and every one passed.

edit:
By the way I'd like to mention I've created a similar PR for PluginSkeleton Sylius/PluginSkeleton#300.

[lchrusciel]

Thanks, Jakub! 🥇