Update openstack-doc-tools

Add new repositories security-doc and training-guides to projects.txt so
that hey are setup properly.

Increase requirement to openstack-doc-tools 0.16.1. Changes compared to
current 0.15:

0.16.1
------

* Fix includes of rackbook.rng to unbreak syntax checking.

0.16
----

* ``openstack-doc-test``: Fix handling of ignore-dir parameter.
* ``autohelp-wrapper``: New tool to simplify the setup of an autohelp.py
  environment.
* ``diff_branches.py``: Generates a listing of the configuration options
  changes that occured between 2 openstack releases.
* ``autohelp.py``: Add the 'dump' subcommand, include swift.
* ``jsoncheck.py``: Add public API.
* Added tool to generate a sitemap.xml file.
* Added script to prettify HTML and XML syntax.

Change-Id: I4e8de158613a2bb1753379b32f5d9fed775b2369
Merge "Update openstack-doc-tools"