* upgrade eslint, all related deps, and config files
* replace gruntify-eslint with basic eslint-cli wrapper
* arrow-IIFEs must be invoked outside of the parens
* move import statements before their use
* reindent to satisfy new indentation check algorithm
* place missing semicolon
* ignore copy-pasted decode geohash code
* [grunt/eslint] fix argument spacing
* [gurnt/eslint] add comment about contents of report
* [grunt/tasks] use `export default`
