.travis.yml in heartcheck-1.1.1 vs .travis.yml in heartcheck-1.2.0

@@ -14,5 +14,7 @@
       gemfile: Gemfile-old-ruby
     - rvm: "2.2.1"
       gemfile: Gemfile-old-ruby
     - rvm: "2.2.2"
     - rvm: "2.3.0"
+    - rvm: "2.3.3"
+    - rvm: "2.4.1"