ractivejs/ractive — pull request #1585 by Rich-Harris (2014-12-17 18:55:47+00:00)
Title: remove support for long-since-deprecated callbacks from promise-returning methods

This PR removes support for the callback in `ractive.set(keypath, value, callback)`, which was deprecated long ago - `ractive.set()` and [various other methods](http://docs.ractivejs.org/latest/promises) return a promise.