* screenshotter: replace promisify(fs) and mkdirp with fs-extra
* screenshotter: replace selenium.promise with builtin Promise
* Lint all JavaScript files in the root
* unicodeMake: replace console.log with writeFile(string)
* unicodeMake: check timestamp, do not build if up-to-date
* Replace check-dependencies with yarn check
* Exclude src/unicodeMake.js from coverage
* Add (missing) dependencies
* Skip CircleCI if only unrelated has been changed
* Fix commit range
* Use fs-extra in update-sri
* chore(package): update css-loader to version 1.0.0
* Require minimum Node 6.9
* Use `postcss-loader` and `cssnano` to minimize CSS
* chore(package): update lockfile
* Remove unnecessary `ident` and function
* chore(package): update cssnano to version 4.0.1