* remove ember-cli-favicon

* link to png favicon in public folder

* skip some things in the build depending on the env

* update to ember-cli 3.5.0 for broccoli 2, and ember-fetch because it was incompatible with broccoli 2

* update some things the new sass module wasn't happy about

* turn off more things in dev to make the build faster

* bump to the latest ember-cli and move back to node-sass

* remove sass since we're using node-sass

* include polyfill in test as well