.travis.yml in icalendar-recurrence-1.1.2 vs .travis.yml in icalendar-recurrence-1.1.3

@@ -1,9 +1,8 @@
 language: ruby
 sudo: false
 rvm:
-  - 2.4.1
-  - 2.3.4
-  - 2.1.7
-  - 2.0.0
-  - 1.9.3
+  - 2.5
+  - 2.4
+  - 2.1
+  - 2.0
 script: bundle exec rspec