Ruby range Culprit in Symfony Yaml solved through str_replace

@jtreminio Previously I had open the issue #958 which was solved by you using alternative way. At that time I was unable to get value in single quote like this `'!ruby/range 10200..10500'` because I was not seeing the symfony code throughly and was directly injecting to the Vagrantfile. Now I have solve this issue in better way through the help of https://github.com/symfony/symfony/issues/11682 solution.

Concept was to `str_replace` the `usable_port_range:` into `usable_port_range: !ruby/range` so that the single quote is removed as because for `10200..10500` type of entry there's no single quote applied automatically. Happy ruby range in symfony programming!
If nil then vagrant default Port Range `Range.new(2200..2500)` will be set.