Upgrading and standardizing versions of Node

[megoth]

Upgrading the default version we're using to build this project from 8.16 to 12.7.

Also adding 8.10 as the lowest version we'll currently support (works with ESLint) so that we know when it breaks (and then fix it or reevaluate which versions we'll support).

package-lock.json is simply the new generated file after upgrading to 12.7.

[Vinnl]

Maybe give Tim a heads-up after merging this, I don't think he uses nvm?

[megoth]

It should work with any versions newer than 8.10, so I think he's good, but yeah, I'll check with him ^_^

[Vinnl]

@megoth Yeah it should work, but with the newer version you'd also get a newer version of npm, and in between the lockfile format changed. So if Tim would continue to use the old version of npm, we'd get a new lockfile with many changes every time someone runs npm install with a different version than the last time the file was generated :)

[RubenVerborgh]

Tim needs to upgrade 😄

@megoth Is DEFAULT_NODE_VERSION still used anywhere? Looks like a leftover from older build scripts.

[megoth]

@megoth Is DEFAULT_NODE_VERSION still used anywhere? Looks like a leftover from older build scripts.

I'll double-check, gotta admit it was shamelessly copied from https://github.com/rdfjs/N3.js/blob/master/.travis.yml#L3-L7 without much though -_-

[megoth]

I can't find any information for why it should be there, so I'll remove it.

[megoth]

@RubenVerborgh I was thinking of switching out npm install with npm ci (npm-ci), which means that we must test with Node v8.12.0 (npm v6.4.1) and Node v10.3.0 (nvm v6.1.0).

I think it would be good to have a clean install and be 100% sure that package-lock.json describes what dependencies to use.

Do you have thoughts on this?

[RubenVerborgh]

Do you have thoughts on this?

npm ci.