fix: Update to node-gyp 7

[adamretter]

node-gyp 7 has some improvements for building on Catalina and building with Python3 etc.

[malept]

This will trigger a semver-major release of electron-rebuild, as node-gyp 7 requires a recent version of Node 10. Please hold off on approving this.

[adamretter]

@malept Isn't a recent version of Node 10 a good idea? Node10 is already no longer actively developed and will soon be EOL - https://nodejs.org/en/about/releases/

[malept]

Yes, however:

1. This needs to be explicit. If this PR was merged as-is, it would be released as a patch, not a major version bump.
2. I have an in-progress branch to update all of the other dependencies that now require Node 10 and I would personally prefer to do all of that together, to avoid multiple version bumps in succession.

[malept]

A workaround for now would be to use yarn resolutions in your projects to resolve any node-gyp dependencies to whatever version you need.

[malept]

I've upgraded node-gyp to version 7 in the version 2 branch, thanks for letting me know about the version bump.

[adamretter]

@malept Is there any sort of timeframe for a version 2 release of electron-rebuild?

[malept]

Roadmap: #356