Update version code from oslo.

Change-Id: Ibe96c6783203dc01d231c5ba990159a089ee27ba
Merge "Update version code from oslo."
Replace custom tearDown with fixtures and cleanup.

testtools.addCleanup is a more resilient way to perform cleanup activities,
as it will continue to clean things up even if there are unforseen problems.

Specifically, replace custom management of tempdirs with fixtures.TempDir
and replace tearDown methods that can be easily replaced with calls to
addCleanup in the setUp method. There are at least two temp dir creations that
did not have a corresponding cleanup in this patch, which is another reason
for using useFixture(fixtures.TempDir) instead of calls to mkdtemp.

Part of blueprint grizzly-testtools.

Change-Id: I4eb548010612bd5a8d30e8e2304fa66d3d5ffb7c
Avoid testtools 0.9.25

Fixes bug 1102400

testtools 0.9.25 introduces a new dependency on the 'extras' package, but
it does so in a way to prevents itself from being installed without the
'extras' package already installed.

Work around the problem for now by avoiding the problematic release.

Change-Id: If8aa3925c744fad88f6f2715b5e779d0c258524c
Update version code from oslo

Pull in a versioning fix from openstack-common, fixes
python setup.py sdist versioning.

Change-Id: I9ffab5c2b37190b4c7daad5e92da40d773c99b4f
Signed-off-by: Chuck Short <chuck.short@canonical.com>