fix missing files

add vendor directory in cdq.gemspec

````
Generating Data Model HelloApp
   Loading schemas/0001_initial.rb
   Writing resources/HelloApp.xcdatamodeld/0001 initial.xcdatamodel/contents
     Build ./build/iPhoneSimulator-7.0-Development
     Build /Users/toshiwo/apps/HelloApp/vendor/bundle/gems/cdq-0.1.3/lib/../vendor/cdq/ext
rake aborted!
No such file or directory @ dir_chdir - /Users/toshiwo/apps/HelloApp/vendor/bundle/gems/cdq-0.1.3/lib/../vendor/cdq/ext/
````