fluent/fluentd — pull request #265 by tagomoris (2014-02-18 15:36:55+00:00)
Title: Add plugin spec helper w/ Rspec and Refinements

* using Refinements to override Fluent::Engine.emit
* rspec style plugin testing is only for Ruby 2.0.0 or later
* we need event_router to hook emits from plugins
* it also needed for EventStream (ErrorStreams)