Async Whilst errors if test() gets false before iteration starts

[blockwooddev]

What version of async are you using?
3.0.1-0

Which environment did the issue occur in (Node version/browser version)
node 8.9.4

What did you do? Please include a minimal reproducable case illustrating issue.
Used async whilst in a case where the test was false on the first try, before calling the iterator.

What did you expect to happen?
After the test is called, I expected to go to callback()

What was the actual result?
Error: undefined is not iterable

From looking at the code, it looks like whilst tries to call spread on result on line 55 if the truth is false. Since next() hasn't been called yet (and won't be called), result is still undefined, so spread gets called on undefined, and the error occurs.