Test with recent Ruby versions on TravisCI

tvdeyen · tvdeyen · commit aa480ca3e311 · 2019-04-01T15:06:57.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,9 +3,9 @@ dist: trusty
 sudo: false
 cache: bundler
 rvm:
-- 2.2.7
-- 2.3.5
-- 2.4.2
+- 2.4.5
+- 2.5.5
+- 2.6.2
 branches:
   only:
     - master
