Tomas Pesek

I forked this repository and update code for symfony3 compatibility. Please, check my commits in repo and give me feedback. I dont know if i should do pull request before...

OK, I sended it, but i apologize in advance if there is something incomprehensible

I think so it could be an easy pick, we have updated the yaml-standards library, so we should just add a checker to https://github.com/shopsys/shopsys/blob/master/yaml-standards.yaml and https://github.com/shopsys/shopsys/blob/master/project-base/yaml-standards.yaml