twitter/kestrel — pull request #136 by eric (2014-02-25 18:55:59+00:00)
Title: Update currentAge for queue on add

Right now `_currentAge` is not updated on a queue until an item is removed.

This means if the queue had items, then went to 0, when the next item is added, the queue age will not reflect the `addTime` of the only item in the queue, but instead the add time of the last item before it went to 0.