don't build rails 3 and rails 4 on ruby 2.4.0

Charlie Somerville · Charlie Somerville · commit 3b209cc43e56 · 2017-01-12T16:28:38.000+11:00
diff --git a/.travis.yml b/.travis.yml
@@ -31,3 +31,7 @@ matrix:
       rvm: 2.1
     - gemfile: gemfiles/rails_5.gemfile
       rvm: 2.0
+    - gemfile: gemfiles/rails_4.gemfile
+      rvm: 2.4.0
+    - gemfile: gemfiles/rails_3.gemfile
+      rvm: 2.4.0
