This patch:
- renames ChromiumDownloader into just Downloader (this is in
preparation for different products download)
- moves Downloader from utils/ to lib/. This unifies all of the
production-critical code in the lib/.
Drive-by: make Downloader a regular class.
This patch:
- reformats codebase to use 2-spaces instead of 4. This will
align the project with other codebases (e.g. DevTools and Lighthouse)
- enables eslint indentation checking
References #19
This patch introduces check_availability.js utility which looks for
available chromium binaries for different revisions and platforms.
This patch also re-factors the chromium downloader scripts so that
it can operate different platforms.
