tools: update ESLint to current version

We have been stalled on ESLint 3.8.0 for some time. Current ESLint is
3.13.0. We have been unable to upgrade because of more aggressive
reporting on some rules, including indentation.

ESLint configuration options and bugfixes are now such that we can
reasonably upgrade.

PR-URL: https://github.com/nodejs/node/pull/10561


Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>