.travis.yml in bootstrap-sass-3.3.5.1 vs .travis.yml in bootstrap-sass-3.3.6

@@ -1,22 +1,25 @@
 language: ruby
+cache: bundler
+bundler_args: --path ../../vendor/bundle --without debug
 rvm:
-  - 2.1.5
+  - 2.2.3
 gemfile:
+  - test/gemfiles/rails_head.gemfile
   - test/gemfiles/sass_3_3.gemfile
   - test/gemfiles/sass_3_4.gemfile
   - test/gemfiles/sass_head.gemfile
 before_install:
+  - "nvm install stable"
   - "npm install"
 matrix:
   allow_failures:
-    # rbx has issues https://github.com/rubinius/rubinius/issues/3060
-    - rvm: rbx-2
+    - gemfile: test/gemfiles/rails_head.gemfile
     - gemfile: test/gemfiles/sass_head.gemfile
 notifications:
   slack: heybb:3n88HHilXn76ji9vV4gL819Y
 env:
   global:
   - VERBOSE=1
 script:
-  - bundle exec rake
-  - sh test/*.sh
+  bundle exec rake && sh test/*.sh
+sudo: false