Update openstack-doc-tools to at least 0.15

Version 0.15 is needed to build the HA guide in openstack-manuals
and to build localized security-guide.

0.15 contains the following changes over 0.13:

0.15
----

* ``openstack-doc-test``: Output information about tested patch,
  special case entity files for book building. Remove special handling
  for high-availability-guide, it is not using asciidoc anymore.
* New script in cleanup/retf for spell checking using the RETF rules.
  patch.
* Fix entity handling in ``openstack-generate-docbook``.

0.14
----

* ``openstack-auto-commands``: Improved screen generation and swift
  subcommand xml output.
* ``openstack-doc-test``: Warn about non-breaking space, enhance
  -v output, special case building of localized high-availability
  guide, fix for building changed identity-api repository.
* New command ``openstack-jsoncheck`` to check for niceness of JSON
  files and reformat them.
* ``openstack-autohelp``: Update the default parameters. The tables
  are generated in the doc/common/tables/ dir by default, and the git
  repository for the project being worked on is looked at in a sources/
  dir by default.

Change-Id: Ib6b0360f4443c80579f2aeba55642c0fbb3da3f6
Add bash8 to global-requirements

Now that bash8 is available on PyPI, we can start using it on OpenStack
projects. Looking to start using bash8 in Keystone bash scripts. Note
that bash8 uses the Apache Software License 2.0.

Change-Id: Ica767630f68f60dc36dba8fd5bf0bce74342b2f2
Updated zake now that zake 0.0.20 is released

The newer zake fixes up watcher usage and makes those work
correctly so that integrating projects can correctly test
that watches are triggered in the correct manner.

This makes it more useful for taskflow & tooz & others that
use this library for testing zookeeper interactions (without
requiring a full zookeeper setup/deployment).

Change-Id: I8973ab25c7b5ad40cf3152df1b43da979ec3c730
Add hacking 0.9.0 series

Hacking 0.9.1 is out (hacking 0.9.0 had a minor bug in it, so its
blacklisted), and we want to start supporting projects to migrate over
to 0.9.x. Expand the upper bound to allow 0.9.x while still
supporting 0.8.x series so we keep the old version in our mirrors as to
not break anything.

Change-Id: I17b7b67135577204de29b82e28526c78d03e8fa5
Merge "Add bash8 to global-requirements"
Merge "Updated zake now that zake 0.0.20 is released"
Merge "Update openstack-doc-tools to at least 0.15"
Merge "Add hacking 0.9.0 series"