See #5 - code in Symfony was reverted

Revert "Updating CHANGELOG and ERRATA with FlattenException changes"

This reverts commit 049c883a6b10cf902d3a592d7850b0076d562299.
See #5 - code in Symfony was reverted

Revert "Switched from deprecated Symfony\Component\HttpKernel\Exception\FlattenException to Symfony\Component\Debug\Exception\FlattenException"

This reverts commit 0098355aa8b489c7a3ae1224922215f3568b66b6.