Created by: bradfordlemley
Several create-react-app scripts assume that the create-react-app packages will be in app/node_modules.
But in a monorepo, e.g. yarn workspace, the create-react-app packages can be hoisted to the top-level node_modules.
This PR fixes those scripts to allow them to find packages at the top-level node_modules.
Fixes #3031 (closed).