Update to symfony/var-dumper ^4.1 and PHP ^7.1

New major release, it's not compatible with PHP 5.5 anymore.

Minor updates

Previous master branch moved to the "legacy" branch to be compatible with PHP ^5.5

Migration to Symfony VarDumper component

1.0

Use Symfony VarDumper instead of std var_dump function

Updated README

0.2

Readme update

First release

0.1

Added some code