Upgrade to Doctrine ORM 3.0 breaks Turbo

[gubler]

I tested upgrading to Doctrine ORM 3.0/DBAL 4.0 and ran into a problem where those packages no longer require doctrine/common but ux-turbo relies on the ClassUtils class from common.

I was able to fix the problem by directly requiring doctrine/common in my project, but I think ux-turbo should require doctrine/common unless there are plans to move away from using the ClassUtils class (I may have missed discussion about this somewhere).