.travis.yml in openbd_api-0.6.0 vs .travis.yml in openbd_api-0.6.1

@@ -1,7 +1,7 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.2.6
-  - 2.3.3
-  - 2.4.0
-before_install: gem install bundler -v 1.14.3
+  - 2.4.6
+  - 2.5.5
+  - 2.6.3
+before_install: gem install bundler -v 2.0.2