.travis.yml in kumogata-0.5.7 vs .travis.yml in kumogata-0.5.8

@@ -1,6 +1,10 @@
+sudo: false
 language: ruby
+cache: bundler
 rvm:
   - 2.0.0
+  - 2.1
+  - 2.2
 script:
   - bundle install
   - bundle exec rake