.travis.yml in react_on_rails-11.3.0 vs .travis.yml in react_on_rails-11.3.1.beta.0

@@ -2,11 +2,9 @@
 
 language: ruby
 
 rvm:
   # Rails 5 requires 2.2
-  - 2.3.8
-  - 2.4.5
   - 2.5.3
   - 2.6.0
   - 2.2.10
 services:
   - docker