Make example code from README runnable, with TonicDev or similar

[pimterry]

Doesn't work in default TonicDev, but works perfectly if you switch Node version to v5.

[tolmasky]

The way we choose the node version in tonic is the engines property in your package json (https://docs.npmjs.com/files/package.json).

[pimterry]

Ah, of course. Yes, that's perfect, seems to work great by default now. Thanks!