What JS release should I transpile to to support V2+ espruino

@Gordon, @fanoush

I've put together a rollup starter repo with buble transforms for features not supported currently plus one pretty simple babal plugin for just async/await. Should work on any device (if you change the npm scripts). The starter currently runs a set of extended feature examples as a "test". With more work this could be made into something more generic which would allow noobs to get going faster with less pain. It will pretty much allow me to use my existing code es6/esm without too much modification nor too much transpiled bloat.

It is structured so that a user works on app.js coding the app class therein for their particular application.

Let me know if you successfully used it or what the issues are (can use github issue tracker). If the idea of a starter like this seems like a good idea then maybe others can help with improvements/upgrades.

https://github.com/dkebler/espruino-star­ter.git