.travis.yml in ridgepole-0.6.5 vs .travis.yml in ridgepole-0.6.6.beta

@@ -3,11 +3,12 @@
 language: ruby
 cache:
   - bundler
   - apt
 rvm:
-  - 2.2.5
-  - 2.3.3
+  - 2.2.7
+  - 2.3.4
+  - 2.4.1
 before_install:
   - gem install bundler
 before_script:
   - sudo service mysql stop
   - sudo service postgresql stop