[crucialfelix]

Related:

for (var key of Object.keys(imps)) { }

I figured that would work with babel-2015 and it did work on Chrome and Safari but on Firefox visitors were getting:

Symbol.Iterator undefined

You need http://babeljs.io/docs/plugins/transform-es2015-for-of/ as well.

So there is much less risk in using _.each(imps, (value, key) => and not having to discover what you don't know.

I also added Firefox to the unit tests after that.