Fix tox job for stress tests.

This commit fixes the behavior of the tox stress job. To do this a
new json tests file was added for the tox job. This json file will
contain a list of all the actions that will get run as part of the
tox job. (and by extension the periodic jenkins stress test job) The
tox job is then updated to run each of the tests listed in the json
file for an hour each.

Part of: blueprint stress-tests

Change-Id: I5eb0652799601631e34cc2bbef836624d71bb3e7
Rework stress to be more UnitTest like

This patch reworks the stress test framework and
the scripts to be a bit more flexible and to be
like how unit tests are written.  Instead of
writing a module that contains functions, we now
write an object that can implement a setUp and tearDown
method.  By default the object's 'run' method will be
called by the driver.

The setUp method will be called prior to calling run
and tearDown will be called after run is stopped.

Also added debug logging to the cleanup mechanism.
Also added removing snapshots prior to removing
volumes during cleanup

DocImpact

Implements:  blueprint stress-tests

Change-Id: I39b8a1d38f70ddda4867126b58bb7053b45654d6
Merge "Rework stress to be more UnitTest like"
Merge "Fix tox job for stress tests."