Using Node v8.9.4

[SamBroner]

I haven't fully vetted it works, but adding "engines": {"node": "8"} to package.json files upgrades functions to running in node v8.9.4. I think getting onto the next LTS is probably worthwhile.

After testing, and with approval I can add a PR.

[sampl]

If you submit one, I'll merge it! Thanks @SamBroner :)