.travis.yml in trollolo-0.2.0 vs .travis.yml in trollolo-0.3.0

@@ -1,12 +1,13 @@
 language: ruby
 cache: bundler
 before_install:
-  - gem --version
   - gem list bundler
 rvm:
   - "2.2.3"
   - "2.3.1"
+  - "2.4.3"
+  - "2.5.0"
 script:
   - 'bundle exec rubocop -D'
   - 'bundle exec rspec spec/unit'
 sudo: false