Update required Node version

[filips123]

Readme says that minimum Node.js version is 10. This is true because of some dependencies which also require version 10. However, in package.json file, minimum version is 8. This is incorrect, so I'm fixing this now.

[alanshaw]

@filips123 I wasn't aware there were modules in the dependencies that weren't Node.js 8 compatible yet - have you encountered issues?

[filips123]

Travis CI test of my package which has this package as a dependency will fail. Some of js-ipfs-http-client dependencies (js-libp2p-crypto) have set Node.js 10 as the minimum. Here is my build in Node.js 8.

I didn't test this with yarn install --ignore-engines (because I don't have Node.js 8 installed), but maybe there aren't any issues. If this is true, js-libp2p-crypto needs to be informed to lower required Node.js version.

I would be great if Node.js 8 would be supported (if possible) because some still use it.

[alanshaw]

Ah yes, ipfs-http-client doesn't actually use libp2p-crypto it just re-exports it for people to use. I'd prefer it if people required it or used the pre-built browser bundle from a CDN if they need it. It would also make for a much smaller ipfs-http-client bundle.

This problem will be resolved by #915. Lets merge this for now and we can revert after #915 is merged.

[alanshaw]

CI failure is unrelated.

[filips123]

Ok, but don't forget to fix #926 which added Node.js 10 requirement to README.

[andremedeiros]

@alanshaw is there anything I can help with bringing engine back to Node 8? It looks like the related PRs have already been merged, and I assume the offending library was taken out.

[alanshaw]

@andremedeiros if you can do the work to verify the library is compatible with Node.js 8 and send a PR that would be great!

[michaelsbradleyjr]

See PR #996.