.travis.yml in usps_flags-0.5.0 vs .travis.yml in usps_flags-0.5.1

@@ -1,7 +1,7 @@
 language: ruby
 rvm:
-  - 2.4.1
+  - 2.5.1
 branches:
   except:
     - "/^v[0-9]+\\.[0-9]+\\.[0-9]+(?:-.*)?/"
 notifications:
   email: