Add ESLint

Winnierequested to merge
(removed):eslint into master

What does this MR do?

  • create package.json
  • add ESLint dependencies to package.json
  • add JavaScript linting to CI
  • add Rake task lint:javascriptas alias for eslint (which itself is an alias for npm run eslint)

Are there points in the code the reviewer needs to double check?

Probably not.

Why was this MR needed?

My hovercraft was full of eels.

What are the relevant issue numbers?

Merge request reports