Switch to stestr

According to Openstack summit session [1],
stestr is maintained project to which all Openstack projects should migrate.
Let's switch to stestr as other projects have already moved to it.

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

Change-Id: I5c4d37afdc438cc978bff37e4d0c56c7ad60fb19

.gitignore

@@ -25,8 +25,7 @@ pip-log.txt
 .coverage
 cover
 .tox
-nosetests.xml
-.testrepository
+.stestr/
 
 # Translations
 *.mo

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./oslo_versionedobjects/tests
+top_path=./

.testr.conf

@@ -1,7 +0,0 @@
-[DEFAULT]
-test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} \
-             OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} \
-             OS_TEST_TIMEOUT=${OS_TEST_TIMEOUT:-60} \
-             ${PYTHON:-python} -m subunit.run discover -t ./ ./oslo_versionedobjects $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

lower-constraints.txt

@@ -31,7 +31,7 @@ msgpack-python==0.4.0
 netaddr==0.7.18
 netifaces==0.10.4
 os-client-config==1.28.0
-oslo.concurrency==3.25.0
+oslo.concurrency==3.26.0
 oslo.config==5.2.0
 oslo.context==2.19.2
 oslo.i18n==3.15.3
@@ -65,9 +65,9 @@ Routes==2.3.1
 six==1.10.0
 smmap==0.9.0
 statsd==3.2.1
+stestr==2.0.0
 stevedore==1.20.0
 tenacity==3.2.1
-testrepository==0.0.18
 testtools==2.2.0
 traceback2==1.4.0
 unittest2==1.1.0

test-requirements.txt

@@ -6,6 +6,7 @@ oslotest>=3.2.0 # Apache-2.0
 testtools>=2.2.0 # MIT
 coverage!=4.4,>=4.0 # Apache-2.0
 jsonschema<3.0.0,>=2.6.0 # MIT
+stestr>=2.0.0 # Apache-2.0
 
 mock>=2.0.0 # BSD
 fixtures>=3.0.0 # Apache-2.0/BSD

tox.ini

@@ -10,7 +10,7 @@ install_command = pip install {opts} {packages}
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/test-requirements.txt
-commands = python setup.py testr --slowest --testr-args='{posargs}'
+commands = stestr run --slowest {posargs}
 
 [testenv:py27]
 basepython = python2.7