.travis.yml in comma-3.0.3 vs .travis.yml in comma-3.0.4

@@ -2,7 +2,8 @@
 rvm:
   - ree
   - 1.8.7
   - 1.9.2
   - 1.9.3
+  - rbx-18mode
 
 script: "bundle exec rake appraisal:install && bundle exec rake appraisal spec"
\ No newline at end of file