Created by: ianschmitz
General cleanup after the Jest 24 PR.
This also includes jsdom@14 via https://www.npmjs.com/package/jest-environment-jsdom-fourteen. Since we have a node >= 8.10 requirement, we are able to use the latest version of jsdom which includes additional implementations of browser APIs such as MutationObserver (which we had an issue filed for over at #6617 (closed)).
/cc @SimenB. Is there more you recommend we do to cleanup our Jest config for TypeScript?