.travis.yml in stateful_enum-0.3.1 vs .travis.yml in stateful_enum-0.4.0

@@ -5,21 +5,15 @@
 cache:
   - apt
   - bundler
 
 rvm:
-  - 2.2.5
-  - 2.3.1
+  - 2.2.6
+  - 2.3.3
+  - 2.4.0
   - ruby-head
 
-matrix:
-  exclude:
-    - rvm: ruby-head
-      gemfile: gemfiles/Gemfile-rails.4.1.x
-    - rvm: ruby-head
-      gemfile: gemfiles/Gemfile-rails.4.2.x
-
 gemfile:
   - gemfiles/Gemfile-rails.4.1.x
   - gemfiles/Gemfile-rails.4.2.x
   - gemfiles/Gemfile-rails.5.0.0
 
@@ -27,7 +21,16 @@
   apt:
     packages:
       - graphviz
 
 matrix:
+  exclude:
+    - rvm: 2.4.0
+      gemfile: gemfiles/Gemfile-rails.4.1.x
+    - rvm: 2.4.0
+      gemfile: gemfiles/Gemfile-rails.4.2.x
+    - rvm: ruby-head
+      gemfile: gemfiles/Gemfile-rails.4.1.x
+    - rvm: ruby-head
+      gemfile: gemfiles/Gemfile-rails.4.2.x
   allow_failures:
     - rvm: ruby-head