Doesn't work with Node 4.7

[mmelvin0]

Your package.json says it should work with Node 4.7 but for some reason use strict was removed from index.js in 3.4.

This cause NodeJS 4.7.1 to throw: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode.

(Of course without any indication of what actually threw that, other than it was probably some Ember addon.)

Reverting to 3.3.2 or adding use strict at the top of index.js fixes the problem.