Welcome! Please use this template for reporting bugs or requesting features. For questions about using Workbox, the best place to ask is Stack Overflow, tagged with [workbox]: https://stackoverflow.com/questions/ask?tags=workbox
Library Affected: workbox-sw, workbox-build, etc.
Browser & Platform: E.g. Google Chrome v51.0.1 for Android, or "all browsers".
Issue or Feature Request Description: Your request here.
When reporting bugs, please include relevant JavaScript Console logs and links to public URLs at which the issue could be reproduced.