.travis.yml in rest-in-peace-2.0.4 vs .travis.yml in rest-in-peace-3.0.0

@@ -1,7 +1,13 @@
 language: ruby
+cache: bundler
 rvm:
   - 1.9.3
   - 2.0.0
   - 2.1.2
+gemfile:
+  - gemfiles/Gemfile.rails-3.2.x
+  - gemfiles/Gemfile.rails-4.0.x
+  - gemfiles/Gemfile.rails-4.1.x
+  - gemfiles/Gemfile.rails-4.2.x
 script:
   - bundle exec rake spec