Implement tree shaking

[jennifer-shehane]

I have converted all these lodash imports in my project from import _ from lodash to import { map, etc } from lodash, but it doesn't seem to have made anywhere near a significant improvement in the file size of my project.

I have heard that tree shaking will help and essentially treat this:

import { map, etc } from lodash

Like this:

import map from lodash/map
import etc from lodash/etc