9387bce560
Ruby builds fetch gems from rubygems.org directly because artifactapi has no RubyGems remote type. - add `gems` package type proxying `https://rubygems.org`-style sources - treat `versions`, `names`, `info/*` and `*specs.4.8.gz` as mutable, `gems/*.gem` and `quick/Marshal.4.8/*.gemspec.rz` as immutable - serve `api/v1/*.json` as `application/json` - add a gem/bundler usage snippet to the UI and a gems e2e caching case Requires unkin/artifactapi#148 (HEAD route; RubyGems probes `HEAD /versions`). Reviewed-on: #142 Co-authored-by: unkin-agent <unkin-agent@unkin.net> Co-committed-by: unkin-agent <unkin-agent@unkin.net>