.travis.yml in opentok-2.3.3 vs .travis.yml in opentok-2.3.4

@@ -1,5 +1,10 @@
+# Get container-based infrastructure
+sudo: false
 language: ruby
+# Travis bug, see https://github.com/bundler/bundler/pull/3559
+cache: bundler
+before_install: gem update bundler
 rvm:
 - 1.9.3
 - 2.0.0
 - 2.1.0
 - 2.2.0