Add support for Symfony 5

[pyrech]

Expected behavior

Compatibility with Symfony 5

Observed behavior

composer.json dependencies prevent Symfony 5 to be installed

As Symfony 5 is about to be released at the end of the month (currently in beta), did you plan to release a new version of this bundle to add the compatibility soon?
If not, I may find the time to make a PR if you need help 🙂

[pyrech]

I just made the PR to add support for Sf 5 👍 #92

[mattdyoung]

Now released in v1.6.0