.travis.yml in plantuml_builder-0.1.0 vs .travis.yml in plantuml_builder-0.1.1

@@ -1,4 +1,11 @@
 language: ruby
 rvm:
-  - 2.2.3
+  - 2.1.10
+  - 2.2.10
+  - 2.3.8
+  - 2.4.5
+  - 2.5.3
+  - 2.6.0
 before_install: gem install bundler -v 1.11.2
+script:
+  - bundle exec rspec