Use modularized Lo-Dash functions

Hey!

This PR updates Lo-Dash to ~2.2 and substitutes the `lodash` module for the modularized Lo-Dash functions introduced in Lo-Dash v2 (specifically, for this module: `lodash.map`, `lodash.flatten`, and `lodash.uniq`).

Unfortunately I had to get rid of the chaining you were using (that part of Lo-Dash isn't modularized), but I believe it is a worthwhile sacrifice for the disk space we save in dependencies :)