Updated openstack/openstack
Project: openstack/taskflow  95cb0625f41c71510459524d5777e726321afef9

Fix doc which should state fetch() usage

The doc should say single results can be fetched with
fetch() and not using the fetch_all() method which is
used for a different purpose.

Change-Id: I57f23f5f3f72336d91aedcb413d4f789a2844b06