Update .travis.yml

oreoshake · oreoshake · commit db5f4dba6140 · 2014-12-17T12:15:07.000-08:00
Use the bundler caching from travis http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/
diff --git a/.travis.yml b/.travis.yml
@@ -7,3 +7,4 @@ rvm:
   - "1.8.7"
 
 sudo: false
+cache: bundler
