ci: use Node 8.2.1 to build binary on Windows CI #1390

[bahmutov]

• appveyor
• buildkite
• check the current Node major against .node-version file

[brian-mann]

So this doesn't happen again... can we add a script that checks the system node matches the .node-version file in the root of the repo?

That way if we do change it but forget to update the system it'll instantly point that out. I know we don't always use exactly 8.2.1 but maybe the script can use semver and sync up the major version?