Update RubyCollector
Update RubyCollector

- Returns list of loaded gems
- Returns Ruby PatchLevel and Revision

nicolas-brousse/rack-webprofiler,nicolas-brousse/rack-webprofiler,rack-webprofiler/rack-webprofiler,rack-webprofiler/rack-webprofiler,rack-webprofiler/rack-webprofiler,nicolas-brousse/rack-webprofiler