Created by: cvrebert
Fixes #18559 (closed).
(Yes, I'm aware mv doesn't work in Windows. This is the least-worst option vs. adding more dependencies, at least until https://github.com/shelljs/shx has a proper release. This only affects the twbs team, not our users. If you absolutely need to run this on Windows, setup an mv=move alias in cmd.)
Note to twbs team: You'll need to npm uninstall npm-shrinkwrap or nuke node_modules/ to eradicate your local uber/npm-shrinkwrap and be able to shrinkwrap properly going forward.