Add Rubinius to travix matrix

Author: seuros

.travis.yml

@@ -3,6 +3,7 @@ rvm:
   - 2.1.2
   - 2.0.0
   - 1.9.3
+  - rbx-2
 
 gemfile:
   - ci/Gemfile.activerecord-4.1.x
@@ -14,6 +15,9 @@ env:
   - DB=sqlite
   - DB=mysql
   - DB=postgresql
+
 script: WITH_ADVISORY_LOCK_PREFIX=$TRAVIS_JOB_ID bundle exec rake --trace all_spec_flavors
+
 allow_failures:
-      - gemfile: ci/Gemfile.activerecord-edge
+      - gemfile: ci/Gemfile.activerecord-edge
+      - rvm: rbx-2