babel-polyfill conflicts

[sibelius]

• babel-polyfill

If another app also adds babel-polyfill it will cause troubles

Uncaught Error: only one instance of babel-polyfill is allowed
    at Object.eval (VM14221 index.js:10)
    at eval (VM14221 index.js:29)
    at Object../node_modules/babel-polyfill/lib/index.js

[jgcmarins]

babel-polyfill is a peerDependencies: https://github.com/entria/react-app-loader/blob/master/package.json#L19