Ungron doesn't respect --no-sort option

[slafs]

When using the --ungron option I'd expect the --no-sort option to take effect too,
but unfortunately it's being ignored.

Example:

$ echo '{"z": "first", "a": "last"}' | gron --no-sort | gron --no-sort --ungron
{
  "a": "last",
  "z": "first"
}

Maybe related to #102 ?

[pbsds]

It think this issue is in reality a request for a --insert-order flag