update: jQuery Cycle2; version: 2.1.5 build: 20140415

Source: https://github.com/malsup/cycle2/releases/tag/2.1.5

Main motivation for updating was that jquery.cycle2.js.map was 404'ing in the last version, so I've added it in. 

- existing structure followed
- package.json all good
- all files minified (except jquery.cycle2.js.map)
- tests pass