Remove async

[phated]

Replace with smaller deps. We only use 2 methods.

[phated]

cc @stevelacy - If you have some time and want to help

[stephenlacy]

I was looking at this one, I replaced one on my local branch but did not find a good replacement for the applyEachSeries

[phated]

Yeah, I vaguely remember thinking I'd need to create a replacement module. I'd need to review to remember everything but I think there could be a better way to implement than applyEachSeries

[phated]

Wrapping this up now. I found a good way to replace it with now-and-later which allows me to reduce the dependency tree even further