Update openstack-doc-tools for Documentation repos

Version 0.11 is current version. This new version
is required to properly build and publish the various
OpenStack documentation repos like operations-guide, api-site and
openstack-manuals.

Change-Id: I37540b106d17d638cf8c1b5a4e9132c18d3f2168
Merge "Update openstack-doc-tools for Documentation repos"