Remove dependence on jQuery

[mboynes]

Assuming it's possible to remove jQuery features without compromising backwards compatibility, we should refactor the code to remove the dependence on jQuery. If a site is not using jQuery otherwise, it makes this plugin much heavier than it needs to be.

[davisshaver]

I'd be game to start this. Wonder what direction we would take.

I'm intrigued by Zepto, an "aerogel-weight" library that replicates jQuery API. http://zeptojs.com/

OTOH Foundation integrated and then removed Zepto, so maybe not worth pursuing: https://zurb.com/blog/why-we-dropped-zepto

Probably makes the most sense to go Babel/es6?