Fixes https://github.com/rodjek/puppet-lint/issues/249 - Variables incorrectly identified as top scope

This affects when parser = future and we are utilising the $foo.each |$var| loops that gives us puppet-lint will throw a warning saying that we are referencing a top scope variable (when in fact we are not).

Not being a puppet-lint pro here, the change i've done seems to circumvent that issue, and i've also added a test for it