js-IPFS early testers programme

We're trying to improve our release process for [`js-IPFS`](https://github.com/ipfs/js-ipfs) and part of that is introducing an early testers programme.

Full details are on the doc at [`ipfs/js-ipfs/doc/EARLY_TESTERS.md`](https://github.com/ipfs/js-ipfs/tree/master/doc/EARLY_TESTERS.md) - if you'd like to join in and help out please send a PR updating that doc to add this repo and we'll open PRs here when new pre-release versions are available for testing.