Fix uploading of prebuilds to the GitHub tag

[aminya]

Travis and Appveyor failed to upload the prebuilds to the GitHub tag.
https://github.com/zeromq/zeromq.js/releases/tag/v5.2.1

Previous failures:
https://ci.appveyor.com/project/zeromq/zeromq-js/builds/38706697
https://travis-ci.org/github/zeromq/zeromq.js/builds/767078872

[aminya]

@captainsafia Hopefully, this will fix the prebuild uploading on GitHub tag creation. I updated the distros to Bionic and explicitly specified Node 12 and Electron 9.4.4 so they don't use some random old version that comes with the distro.

[aminya]

I think, after merging this, the previous GitHub tag should be deleted and a new one should be created with the same v5.2.1 version. After that, they hopefully start to upload again. 🤞🏻

[captainsafia]

@aminya Thanks for the speedy fix! I'll merge this once the CI passes and push those tags again.

[aminya]

You're welcome! The Electron builds, which we need, are green. One of the tests on Mac is flaky, which may need some retrying in Travis.

[captainsafia]

OK -- let's merge this and give it a go.

[captainsafia]

Looks like it's not picking up the latest Appveyor config in the tag.

I'll just go ahead and create a new one and see if that does the trick.

[captainsafia]

Errrm -- it looks like something is afoot with publishing the assets up to the GH tag.

[n-riesco]

It looks like nodejs/node#33688 , but Appveyor is using v12.20.1 (that should have the fix).
Would using v14 be an option?

[aminya]

Yes, I made a PR. See this:
#447