Fixes parseError from drive API

Without this fix, I get the following error from the API:

```ruby
{"error"=>{"errors"=>[{"domain"=>"global", "reason"=>"parseError", "message"=>"This API does not support parsing form-encoded input."}], "code"=>400, "message"=>"This API does not support parsing form-encoded input."}}
```

It seems [other people](http://stackoverflow.com/questions/11796827/how-to-create-an-empty-google-doc-spreadsheet?lq=1#comment28457776_11804699) are affected by this as well.