Replace JSHint `predef` with `globals`

It looks like `predef` was deprecated in favor of `globals` quite a while ago.

For reference:
* https://github.com/jquery/jquery/pull/1185,
* https://github.com/gruntjs/grunt-contrib-jshint/blob/1fb8000baccb1fedf51c55cdac56f86cac023ad1/tasks/jshint.js#L28-L34