Move away from coffeescript in favor of ES 2015

[cmckni3]

[cmckni3]

@cmbankester Is this finished?

[cmbankester]

No, unfortunately, it is not. It's been on the backburner for effectively a year now. Take a look at the feature/refactor branch. I did make a lot of progress, but even some of that progress is now dated (e.g. gulp).

Dammit, JavaScript ecosystem.

Mainly what needs to be done at this point is testing the converted code.