.travis.yml in shallow_attributes-0.9.0 vs .travis.yml in shallow_attributes-0.9.2

@@ -2,13 +2,16 @@
 sudo: false
 cache: bundler
 before_install: gem install bundler -v 1.11.2
 rvm:
   - 2.0.0
-  - 2.1.8
-  - 2.2.4
-  - 2.3.0
+  - 2.1.9
+  - 2.2.5
+  - 2.3.1
+  - 2.4.0
   - jruby-head
   - rbx-2
+  - ruby-head
 matrix:
   allow_failures:
     - rvm: rbx-2
+    - rvm: ruby-head