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: Ibbad6f4e63efbef4e2e144f3ba4218ce6579371a

.gitignore

@@ -15,7 +15,7 @@ sdist
 .cache
 .coverage
 .tox
-.testrepository
+.stestr/
 
 # pbr generates these
 AUTHORS

.stestr.conf

@@ -0,0 +1,4 @@
+[DEFAULT]
+test_path=./tests
+top_dir=./
+

.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

@@ -39,7 +39,7 @@ snowballstemmer==1.2.1
 Sphinx==1.6.5
 sphinxcontrib-websupport==1.0.1
 stevedore==1.20.0
-testrepository==0.0.18
+stestr==2.0.0
 testtools==2.2.0
 traceback2==1.4.0
 unittest2==1.1.0

test-requirements.txt

@@ -12,7 +12,7 @@ pylint==1.7.1 # GPLv2
 
 reno>=2.5.0 # Apache-2.0
 openstackdocstheme>=1.18.1 # Apache-2.0
-testrepository>=0.0.18 # Apache-2.0/BSD
+stestr>=2.0.0 # Apache-2.0
 
 # mock object framework
 mock>=2.0.0 # BSD

tox.ini

@@ -12,7 +12,7 @@ deps = scrapy>=1.0.0
        -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:pep8]
 commands =