Update async to version 1.4.2
Created by: greenkeeperio-bot
async just published its new version 1.4.2, which is not covered by your current version range.
If this pull request passes your tests you can publish your software with the latest version of async – otherwise use this branch to work on adaptions and fixes.
Happy fixing and merging
This pull request was created by greenkeeper.io. It keeps your software, up to date, all the time.Tired of seeing this sponsor message? Upgrade to the supporter plan! You'll also get your pull requests faster