.travis.yml in webidl-0.1.8 vs .travis.yml in webidl-0.1.9

@@ -1,8 +1,6 @@
 rvm:
-  - 1.9.3
-  - 2.0.0
-  - 2.1.0
+  - 2.2.5
   - ruby-head
 matrix:
   allow_failures:
     - rvm: ruby-head
\ No newline at end of file