.travis.yml in splay_tree-0.1.0 vs .travis.yml in splay_tree-0.2.0

@@ -3,9 +3,10 @@
 script: "bundle exec rake ci"
 rvm:
   - 1.9.3
   - 2.0.0
   - 2.1.0
+  - 2.2.0
   - ruby-head
 matrix:
   include:
     - rvm: jruby-19mode
     - rvm: jruby-20mode