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: I78a93c29f2c9033bba1859c79d826578d72257f5

.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_serialization/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 ./ . $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

lower-constraints.txt

@@ -36,8 +36,8 @@ requests==2.14.2
 requestsexceptions==1.2.0
 six==1.10.0
 smmap==0.9.0
+stestr==2.0.0
 stevedore==1.20.0
-testrepository==0.0.18
 testtools==2.2.0
 traceback2==1.4.0
 unittest2==1.1.0

test-requirements.txt

@@ -5,6 +5,7 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 ipaddress>=1.0.17;python_version<'3.3' # PSF
 mock>=2.0.0 # BSD
 netaddr>=0.7.18 # BSD
+stestr>=2.0.0 # Apache-2.0
 
 oslotest>=3.2.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0

tox.ini

@@ -8,7 +8,7 @@ deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
-commands = python setup.py testr --slowest --testr-args='{posargs}'
+commands = stestr run --slowest {posargs}
 
 [testenv:py27]
 basepython = python2.7