Adds PHP-CS-Fixer as dev dependency

https://github.com/fabpot/PHP-CS-Fixer
[travis] Update script for get php-cs-fixer from Composer install
Merge branch 'hotfix/php-cs-fixer' of github.com:Maks3w/zf2 into Maks3w-hotfix/php-cs-fixer
Close #5281