update ruby version

KieranHayes · KieranHayes · commit f29912dcc229 · 2018-07-04T13:04:28.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,4 +3,4 @@ language: ruby
 cache: bundler
 script: "bundle exec jekyll build"
 rvm:
-  - 2.2.5
+  - 2.3
