Benchmarks

Since I'm obsessed with performance, here is a tiny benchmark comparing the performance of the 0.3.1 version and the current version written in ES6

Description	Library	Op/s	%
simple dependency chains	0.3.1 version	66,722.22	8%
	current version	837,416.60	100%
slightly more complex chains	0.3.1 version	24,530.85	6%
	current version	386,620.50	100%