Ruby Gem Platform Specificity

[dometto]

FYI: Just noticed that when running the app under JRuby, latest_version for RedCloth returns 4.2.3, as that is the latest version available for the platform, and Gem::SpecFetcher is, well, platform-specific. The latest version on MRI is (somwhat confusingly) 4.3.2.

This is not a bug as such, since something is indeed amiss: the newest JRuby version is older than the required version. So it's correctly showing up in ':unknown'.

However, it's good to be aware of this: if you run the app on MRI, this would not have showed up. The only thing we could, at some point, consider implementing is trying to find platform-specific latest versions based not on the platform on which the app is running, but on the ruby version set in the gemfile/gemspec, if it is indeed set. That would require implementing gemnasium/gemnasium-parser#30

(Feel free to close, or not if you think we should do something with this -- either in terms of improving the behavior, or documenting it)