Docstrings from fetch_data method needs to be updated

[WillFuks]

Hello,

Recently a question was posted in SO asking about the return params of the fetch_data method of `QueryResults' in BigQuery client.

As it seems, the return is no longer a tuple with 3 values but rather an object of the class HTTPIterator. Looks like the docstrings needs to be updated (if it could describe some quick example of how to use the iterator it'd be quite helpful :)!)

Thanks,

[lukesneeringer]

Hi @WillFuks,
Thank you for reporting this. We will get that updated.

[ryan-schroeder]

Thanks! I was about to post a question regarding this as well, cheers! =) Thanks for all your work on this.
(Edit, the docs still show the old return value; do these docs generate from the docstrings? https://googlecloudplatform.github.io/google-cloud-python/stable/bigquery-query.html#google.cloud.bigquery.query.QueryResults.fetch_data)