There's a dependency on underscore in the generated prebundle.js file.
var _ = require('underscore');
It's a little confusing since underscore isn't listed as a dependency in the package.json file of the generated app. This seems to work, currently, because underscore is a peer dependency of react-page-objects. This causes npm to put underscore in the top-level of the node_modules folder.
Maybe update the script to use lodash instead, since it's already a dependency of the generated app. It would future-proof the generated app if underscore ever is removed as a peer dependency.