Run tests & prebuild for node 16

[pimterry]

This PR changes the specific node versions that are tested and prebuilt, to add support for node 16.

This also stops pinning v14 builds to v14.2 (originally pinned in #16 (comment)). That was due to an appveyor issue that seems to now be resolved.

In the medium term I expect that moving to N-API would be good, if that's possible, so none of this is necessary, but in the short term updates like this are quick and easy 😃.

[pimterry]

Test errors here are a failure to resolve nodejs.org and a network timeout, I think appveyor is just having a blip.

I tested it separately on appveyor a couple of times before this PR, and it does all build successfully: https://ci.appveyor.com/project/pimterry/win-version-info/builds/39409627.

[vweevers]

In the medium term I expect that moving to N-API would be good

That's what I prefer as well, it's only blocked by lack of time atm.

but in the short term updates like this are quick and easy

👍

I think appveyor is just having a blip

Probably yes. I triggered a retry.

[pimterry]

I triggered a retry.

All passing now! @vweevers Looks like this is all good to merge & release if you're happy with it 👍

[vweevers]

Release build failed - https://ci.appveyor.com/project/vweevers/win-version-info/builds/39500373/job/e4b3kvcbknxi233t - unrelated to this PR because I also upgraded prebuild-install (4.0.0). At first glance it looks like it's attempting (and failing) to build a beta release of electron for some reason. Will look at that later.

[vweevers]

(it might be easier to just switch to N-API though 😄)

[pimterry]

Haha, fun fun fun. Up to you, if switching to N-API is easier than fixing the Electron build then that makes a lot of sense to me!

In case you're looking for even more build admin work 😃 I'd maybe consider switching to GitHub actions if you're swapping everything around anyway? I've been steadily migrating all my appveyor projects onto their windows runners, it's been easy to do and the UX/stability/performance is much better.

[vweevers]

Yes, no question! I'm a fan of GHA too.