Add test that "MIN_NODE_VERSION" is correct

[tunnckoCore]

Just noticed that in one source it is 8 (but in readme says 6) and in another source is 6.

So we can do it a bit more error-proof by requesting (in some step, on build or whatever) https://nodejs.org/dist/index.json filter where .lts is string (LTSes are strings, non-LTS are false) and get the first 2 items (last 2 Active LTS releases, since there's always only two LTSes) and get the lower one (i believe the last one from this 2-item array).

But anyway, it might be too much overkill, but... yea, simple PRs from time to time would be easier :D

[FredKSchott]

Thanks for calling this out, looks like it was updated to latest LTS in some places but not others.

I think you're right that this would be overkill for the build flow, but I could see it being a useful test in this repo (if DEFAULT === LTS in https://nodejs.org/dist/index.json)