.travis.yml in squash_matrix-1.0.3 vs .travis.yml in squash_matrix-1.0.4

@@ -1,5 +1,5 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.3.3
+  - 2.5.3
 before_install: gem install bundler -v 1.16.2