Remove lodash/memoize dependency

[KnutHelland]

@gaearon Whyyyy import another (big) module for memoizing two functions that basically are just constants (pure functions with no arguments)??

This is just picking, and I know you probably aren't actively maintaining this project. But since I stumbled upon it, and since I know you are into optimizing nowadays, I just wanted to mention it. 😃

I'm also very inspired of this one right now: nolanlawson.com The Cost of Small Modules Just think about how extremely much overhead you are putting on something that is basically just a constant value anyway 😮

[gaearon]

Sure, sounds good. I’ll leave it to @kesne to review/release.