Electron version-based regressions

[malept]

While trying to get Electron Packager switched over to use @electron/get instead of electron-download, I found some regressions related to Electron versions:

• chromedriver special case for Electron < 1.7.0: https://github.com/electron/get/blob/29708b9b79a2341ac53e4121022390abfedcd66a/lib/index.js#L102-L107
• Checksums started getting generated in Electron 1.3.2: https://github.com/electron/get/blob/29708b9b79a2341ac53e4121022390abfedcd66a/lib/index.js#L176

The second bullet point is causing Electron Packager tests to fail.

I suppose the question becomes, what Electron versions should tools support? (Which inevitably becomes a topic for the Docs & Tools WG...) Electron Packager tries to support as many Electron versions as possible; there are still some conditionals for the super-ancient 0.37.x series.

[malept]

We discussed this in the Docs & Tools WG meeting today. We're going to only "officially" support the versions of Electron officially supported by the Electron team. If it happens to work with earlier versions, that's great, but we're not going to be actively supporting old versions (as in the examples above).