Switch to using stestr

According to Openstack summit session [1] stestr is
maintained project to which all Openstack projects
should migrate.
Let's switch it then.

[1] https://etherpad.openstack.org/p/YVR-python-pti

Change-Id: I39e56868bb974b4f84986581d2436ca5791a092b
Signed-off-by: Charles Short <zulcss@gmail.com>

.gitignore

@@ -32,6 +32,7 @@ pip-log.txt
 .tox
 nosetests.xml
 .testrepository
+.stestr
 .venv
 cover
 

test-requirements.txt

@@ -11,4 +11,4 @@ oslotest>=3.2.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
-os-testr>=1.0.0 # Apache-2.0
+stestr>=1.0.0 # Apache-2.0

tox.ini

@@ -17,7 +17,7 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
            find . -type f -name "*.pyc" -delete
-           ostestr {posargs}
+           stestr run {posargs}
 whitelist_externals = find
 
 [testenv:pep8]