After burning a lot of time getting all the javascript tooling I wanted working, for the umpteenth open source front-end javascript library I wanted to publish, I threw together this:

https://github.com/krakenjs/grumbler

Pretty opinionated on the tooling it uses, but good if you just want to say "Fuck it, I want to fork some boilerplate, write some code, and build/distribute it", then worry about the finer details later, and swap in specific tooling that you need later.