Echo JS 0.11.0

You are correct, I apologize.  I will note, that `undefined` assignment is faster than deletion.  I wasn't able to get a good/consistent memory profile for comparison.  I was mistaken about how Array is implemented from a couple articles that I'd read, the impression was slice would only effect the starting index and the number of items in the array affected, not the entire series.

Depending on how big the queue might get, it might be worth exploring using a linked-list instead of object refs.

https://github.com/tracker1/queue-testing