.travis.yml in in_threads-1.2.0 vs .travis.yml in in_threads-1.2.1

@@ -4,9 +4,7 @@
   - 1.9.2
   - 1.9.3
   - 2.0.0
   - jruby-18mode
   - jruby-19mode
-  - rbx-18mode
-  - rbx-19mode
   - ree
 script: "bundle exec rspec"