Update travis.yml to support TravisCI changes

* add 'sudo: false' to allow the tests to be run faster on containerized
  infrastructure
* add 'before_install: ...' to install the latest version of bundle the
  the version installed with Ruby v1.9.3 does not appear to be working
  as expected. This issued is described here:
  - travis-ci/travis-ci#5239

.travis.yml

@@ -1,8 +1,10 @@
-
 language: ruby
 rvm:
   - 1.9.3
   - 2.0.0
+sudo: false
+before_install:
+  - gem install bundler
 script:
   - bundle exec rspec spec
   - bundle exec cucumber