chore(travis): node js version should between quotes

saiqulhaq · petebacondarwin · commit 0edde11d781e · 2014-08-20T18:47:43.000+01:00
node js version should between quotation marks based on http://docs.travis-ci.com/user/languages/javascript-with-nodejs/ Closes angular#213
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-  - 0.10
+  - "0.10"
 
 before_script:
   - export DISPLAY=:99.0
