.travis.yml in hako-0.6.1 vs .travis.yml in hako-0.7.0

@@ -1,9 +1,10 @@
 language: ruby
 sudo: false
 rvm:
-  - 2.1
-  - 2.2
+  - 2.1.8
+  - 2.2.4
+  - 2.3.0
   - ruby-head
 before_install:
   - gem install bundler
 matrix:
   allow_failures: