.travis.yml in hanko-0.1.3 vs .travis.yml in hanko-0.1.4

@@ -1,9 +1,15 @@
 language: ruby
+before_install:
+  - gem install bundler
+before_script:
+  - bundle update
+cache: bundler
 rvm:
   - 2.0.0
-  - 2.1
-  - 2.2
+  - 2.1.8
+  - 2.2.4
+  - 2.3.0
   - ruby-head
 before_install: gem install bundler -v 1.10.6
 gemfile:
   - gemfiles/rails3.gemfile
   - gemfiles/rails40.gemfile