Does `animated` need `es6-set`?

[necolas]

In react-native there is a tiny shim for Set https://github.com/facebook/react-native/blob/235b16d93287061a09c4624e612b5dc4f960ce47/Libraries/Animated/src/polyfills/Set.js. Looks like es6-set is going to have a more significant impact on bundle size, so I'm curious if you think it's really needed or if the 'polyfill' would do the job.