.travis.yml in fluent-plugin-exec_cron-0.0.2 vs .travis.yml in fluent-plugin-exec_cron-0.0.3

@@ -1,15 +1,15 @@
 language: ruby
 
 rvm:
   - 1.9.3
   - 2.0.0
-  - 2.1
+  - 2.1.*
+  - 2.2.*
 
-os:
-  - linux
-  - osx
-
 gemfile:
   - Gemfile
+
+before_install:
+  - gem update bundler
 
 script: 'bundle exec rake test'