.travis.yml in outbox-rails-0.5.0 vs .travis.yml in outbox-rails-0.5.1

@@ -1,10 +1,10 @@
 sudo: false
 cache: bundler
 language: ruby
 rvm:
- - 2.2.6
- - 2.3.3
- - 2.4.1
+  - 2.2.6
+  - 2.3.3
+  - 2.4.1
 script:
   - bundle exec rubocop
   - bundle exec rspec