Merge pull request googleapis#600 from localheinz/feature/cache

Enhancement: Cache dependencies between builds

Author: tbetbetbe

.travis.yml

@@ -10,6 +10,10 @@ env:
 
 sudo: false
 
+cache:
+  directories:
+    - $HOME/.composer/cache
+
 php:
   # Can't test against 5.2; openssl is not available:
   # http://docs.travis-ci.com/user/languages/php/#PHP-installation