Update local portability task to test on 1.8.7, 1.9.2, ree, rbx and j…

…ruby

Rakefile

@@ -8,7 +8,7 @@ task :default => :spec
 namespace(:spec) do
   desc "Run all specs on multiple ruby versions (requires rvm)"
   task(:portability) do
-    %w[1.8.7 1.9.2].each do |version|
+    %w[1.8.7 1.9.2 ree rbx jruby].each do |version|
       system <<-BASH
         bash -c 'source ~/.rvm/scripts/rvm;
                  rvm #{version};