.travis.yml in rexec-1.6.1 vs .travis.yml in rexec-1.6.2

@@ -1,8 +1,6 @@
 language: ruby
 rvm:
-  - "1.8.7"
-  - "1.9.2"
   - "1.9.3"
   - "2.0"
-  - rbx-18mode
   - rbx-19mode
+  - rbx-20mode