.travis.yml in webhook_system-2.1.4 vs .travis.yml in webhook_system-2.1.5

@@ -9,12 +9,13 @@
 gemfile:
   - gemfiles/rails_4.gemfile
   - gemfiles/rails_5.gemfile
   - gemfiles/rails_5_2.gemfile
 
-
 matrix:
   exclude:
+  - rvm: 2.5.3
+    gemfile: gemfiles/rails_4.gemfile
   - rvm: 2.1.8
     gemfile: gemfiles/rails_5.gemfile
   - rvm: 2.1.8
     gemfile: gemfiles/rails_5_2.gemfile