JRuby 9.0.0.0 now available on Heroku

Change effective on 22 July 2015

The Ruby stack now supports JRuby 9.0.0.0. To use this release, add the following code to your Gemfile:

ruby '2.2.2', :engine => 'jruby', :engine_version => '9.0.0.0'

The JRuby 9.0.0.0 release notes can be found on the JRuby website.