Update eslint to 5 (Major)

[papandreou]

It currently works, except for the unmet peer dep (which makes npm install fail with npm 2.x/node.js 4), and this warning:

(node:29919) [ESLINT_LEGACY_OBJECT_REST_SPREAD] DeprecationWarning: The 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' option is deprecated. Use 'parserOptions.ecmaVersion' instead. (found in "pretty-standard")

I suggest dropping support for earlier eslint versions so that we can avoid conditionally applying this patch:

standard/eslint-config-standard@6a89a51

TODO:

• Await Add support for eslint 5 jsx-eslint/eslint-plugin-react#1843 and update eslint-plugin-react

[sunesimonsen]

This should be a major version bump

[papandreou]

Yeah, agreed (I put it in the title of the PR :)

[sunesimonsen]

@papandreou I added you and @gustavnikolaj as collaborators and package owners, so just merge and release this 🚢

[papandreou]

@sunesimonsen, thanks a bunch!

[sunesimonsen]

It is nice to have major in the title if we are going for a changelog.

That makes it much easier to see which PR's is breaking.

[papandreou]

@sunesimonsen, I changed it to a label, but that's a good point, let's keep it in the title as well :)

[papandreou]

jsx-eslint/eslint-plugin-react#1843 was merged, awaiting a new release.