.travis.yml in ogp-0.4.0 vs .travis.yml in ogp-0.5.0

@@ -1,8 +1,10 @@
 sudo: false
 
 language: ruby
 
 rvm:
-  - 2.3
+  - 2.7.3
 
-script: "bundle exec rake spec"
+script:
+  - bundle exec rake spec
+  - bundle exec rubocop