Workbox 2.0.3

What's new?

The 2.0.3 release adds babel-preset-env-based transpilation into the build process for our browser libraries, currently targeted at compatibility with Chrome 51 and above. Following this change, the Workbox libraries should work within Samsung Browser 5 (which shares code with Chrome 51), while maintaining its existing compatibility with "evergreen" browsers.

Bug Fixes

• Using async, await makes workbox without further transpilation break on Samsung Internet (Thanks to @HenrikJoreteg for reporting!)