Resolve concurrency issue with Tox

The swap to oslo for concurrency actually stopped the tests from running
properly.  This swaps back so that the tests are run once again.

Change-Id: I3ce060a2183820244aa5b4749e97c17c04a498a3

tox.ini

@@ -12,7 +12,7 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
        -egit+https://github.com/openstack/nova#egg=nova
        -egit+ssh://***REMOVED***:29418/python-powervm.git#egg=python-powervm
-commands = python -m oslo.concurrency.lockutils python setup.py testr --slowest --testr-args='{posargs}'
+commands = python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
 commands = flake8