Updated composer.json to allow phpunit >= 3.7

* You cannot force your projects yo use version > 4 when you really
don't need this version. If you can run your tests with version 3.7.x
you should allow its installation (more version compatibility)
* Also fixed the composer indentation
Added some CS fixes and format

* Added file header to all php files
* Also added all php class headers
* Used php-cs-fixer to all php files
* sorted use statements, grouped by symfony and Egulias, alph asc