Switch to eslint

[compwright]

jshint is no longer actively maintained, and has security vulnerabilities.

Since eslint requires Node.js 6+, this PR drops support for Node.js 4-5.

[thomseddon]

Thanks, this has been fixed in #511

[compwright]

@thomseddon I'm glad you're working on this, but I'm puzzled why you declined mine, especially since mine fixes all the security issues that npm audit warns about, and #511 does not (yet). I've left feedback on that PR where it could be improved.

[thomseddon]

Hmm, maybe I was too rash with this! I hand't noticed that jslint was dead and assumed all the line changes were superfluous - now I see they were actually lint fixes! Which makes this even more awesome.

Will close #511 in preference for this

[thomseddon]

Only issue I can see is that eslint doesn't seem work with node 4.

Is there any way we can keep support?

[compwright]

@thomseddon IMO, it's time to move on. Node 4 is EOL. Perhaps this should be released as 3.1 instead of 3.0.1. I'll update engines.

[mjsalinger]

@thomseddon I think we should drop support for node 4. Node 4 is EOL and no longer supported by node core. In general we should support the versions that are considered active by node.js - so currently, it's 6, 8, and 10..

[thomseddon]

👍 to drop support for 4, all looks good LGTM

[mjsalinger]

A point was made in #496 that we should merge non-breaking changes into 3.1.0 (especially since we're dropping support for 4.x) before making a non-breaking release. Can we refactor this PR to support 4.x for now? We'll drop support for 4.x very soon.

[mjsalinger]

@compwright Can you rebase your changes against the dev branch and fix conflicts? I'd like to merge the eslint change into 4.x..

[compwright]

@mjsalinger good to go! Thanks

[mjsalinger]

LGTM