.travis.yml in dotiw-3.1.1 vs .travis.yml in dotiw-4.0.0

@@ -1,11 +1,27 @@
 rvm:
+  - 2.4.0
   - 2.3.0
   - 2.2.4
   - 2.1.8
   - 2.0.0
-  - 1.9.3
   - jruby-19mode
+gemfile:
+  - gemfiles/rails_4.gemfile
+  - gemfiles/rails_5.0.gemfile
+  - gemfiles/rails_5.1.gemfile
 before_install:
   - gem update --system
   - gem update bundler
 install: "bundle install"
+
+matrix:
+  exclude:
+    # Rails 5 requires Ruby >= 2.2.2
+    - rvm: 2.0.0
+      gemfile: gemfiles/rails_5.0.gemfile
+    - rvm: 2.0.0
+      gemfile: gemfiles/rails_5.1.gemfile
+    - rvm: 2.1.8
+      gemfile: gemfiles/rails_5.0.gemfile
+    - rvm: 2.1.8
+      gemfile: gemfiles/rails_5.1.gemfile