Require babel's ES6 modules from node.
With the release of babel@6 the way generated modules work now does NOT set the module.exports property; instead it sets exports.default. Of course this basically breaks everything trying to require() it. So this tiny module is a replacement for require() for node-based runtimes that imports the default if an ES6 module is detected. A necessary evil it seems, given this behavior is not changing: babel/babel#2212.