This commit also swaps in yarn for npm and tweaks circle ci a bit.
* appveyor.yml first go
* changing node
* ps
* narrow it down
* trying this
* fix airbnb module
* trying with yarn
* logging
* hybrid?
* trying yarn w/circle
* bump workers?
* build off?
* updating script
* tweaking script for appveyor
* bumping maxworkers
* cleaning up
* build step?
* yarn it
* added appveyor badge
