.travis.yml in ffprober-0.3.6 vs .travis.yml in ffprober-0.3.7

@@ -9,7 +9,7 @@
 rvm:
   - 1.9.3
   - 2.0.0
   - 2.1.0
   - jruby-19mode
-  - rbx
+  - rbx-2
   - ruby-head