🐛 (fix) Include early hints requests

[benschwarz]

In this PR:

• Include @soulgalore Include earlyHints served from cache. #116
• Add test data including early hints requests
• Add fromDiskCache, fromEarlyHints, fromServiceWorker, fromPrefetchCache to each entry response object
• Replace bluebird dependency in favor of native promises

Closes #115

[benschwarz]

@soulgalore apologies for including more than one thing in this PR. I got carried away with the bluebird removal (and it was larger than I intended).

[soulgalore]

Hehe no problem @benschwarz thanks a lot!