.travis.yml in heartcheck-1.0.8 vs .travis.yml in heartcheck-1.0.9

@@ -4,8 +4,9 @@
   - "2.0.0"
   - "2.1.0"
   - "2.1.5"
   - "2.2.1"
   - "2.2.2"
+  - "2.3.0"
 install: bundle install -j 4 --retry 3
 script:
   - bin/rspec