.travis.yml in fluent-plugin-gcloud-pubsub-custom-1.3.2 vs .travis.yml in fluent-plugin-gcloud-pubsub-custom-1.4.0

@@ -1,10 +1,11 @@
 language: ruby
 
 rvm:
-  - 2.4.6
-  - 2.5.5
-  - 2.6.3
+  - 2.4
+  - 2.5
+  - 2.6
+  - 2.7
   - ruby-head
 
 gemfile:
  - Gemfile