Fixes #3 - Update Travis

* Removes Ruby 1.9.2 and adds 2.1.0
* Updates Rubinius version
* Sets Bundler caching

.travis.yml

@@ -1,13 +1,8 @@
 language: ruby
+cache: bundler
 rvm:
-  - 1.9.2
   - 1.9.3
   - 2.0.0
-  - jruby-19mode # JRuby in 1.9 mode
-  - rbx-19mode
-#  - 1.8.7
-#  - jruby-18mode # JRuby in 1.8 mode
-#  - rbx-18mode
-
-# uncomment this line if your project needs to run something other than `rake`:
-# script: bundle exec rspec spec
+  - 2.1.0
+  - jruby-19mode
+  - rbx-2