.travis.yml in tokogen-0.1.2 vs .travis.yml in tokogen-0.2.1

- old
+ new

@@ -1,8 +1,10 @@
 sudo: false
 language: ruby
 rvm:
   - 2.3.1
+  - 2.3.3
+  - 2.4.0
 before_install: gem install bundler -v 1.13.6
 install:
   - bundle install --retry=3
   - gem install rubocop
 script: