Created by: bugzpodder
All e2e tests passes locally, trying out CI builds with this PR since I can't merge directly to the other two PRs.
Three new changes:
- Disabled concatenateModules in production build because it breaks WebpackManifestPlugin https://github.com/facebook/create-react-app/pull/4077#issuecomment-389270627
- Changes jsdom options to fetch stylesheet links properly (instead of causing a timeout)
- Fixed inline/external CSS validation in kitchensink test. https://github.com/facebook/create-react-app/pull/4481#issuecomment-390110440