Update to use same technique as proposed changes to kitchen-sink-helpers.
Update to use same technique as proposed changes to kitchen-sink-helpers.

See: https://github.com/joliss/broccoli-kitchen-sink-helpers/pull/7

ember-cli/broccoli-caching-writer,jasonmit/broccoli-caching-writer,twokul/broccoli-caching-writer,joliss/broccoli-caching-writer,stefanpenner/broccoli-caching-writer,chadhietala/broccoli-caching-writer