Update dependency on nikic/php-parser

[kayneth]

Hi,

Is it possible to update to 4.0.0 of nikic/php-parser ? Or do you want to support running on PHP >= 5.5 ?

This question because i want to use Constant Expression evaluation.

For now, there's errors on projects where, in form types, we use constants or declare forms as services to add parameters (we're using an array registered in a Yaml array in parameters).
Current FormTypeChoices Visitor doesn't support this kind of behavior as said in #76.

Thank you :)

Edit : Sorry, i didn't see that the 4.0 version of this repository is from 14 hours ago. Ahah.

[Nyholm]

It sounds like we should do some work to support 4.0.

Good idea!