.travis.yml in openbd_api-0.3.2 vs .travis.yml in openbd_api-0.3.3

@@ -1,6 +1,7 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.3.0
+  - 2.2.6
+  - 2.3.3
   - 2.4.0
 before_install: gem install bundler -v 1.14.3