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: I255684ebe0c2d59c4141eeec12ac346bfcf477b2

.gitignore

@@ -10,7 +10,7 @@ AUTHORS
 ChangeLog
 .projects*yaml
 .projects*.pkl
-.testrepository
+.stestr/
 doc/source/archive_toc.rst
 doc/source/*/*.rst
 doc/source/ptl.rst

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./openstack_election/tests
+top_dir=./

.testr.conf

@@ -1,8 +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:-160} \
-             ${PYTHON:-python} -m subunit.run discover -t ./ ${OS_TEST_PATH:-./openstack_election/tests} $LISTOPT $IDOPTION
-
-test_id_option=--load-list $IDFILE
-test_list_option=--list

test-requirements.txt

@@ -8,5 +8,5 @@ hacking<0.12,>=0.11.0 # Apache-2.0
 yamllint
 mock>=2.0.0 # BSD
 oslotest>=1.10.0 # Apache-2.0
-testrepository>=0.0.18 # Apache-2.0/BSD
+stestr>=2.0.0 # Apache-2.0
 testresources>=2.0.0 # Apache-2.0/BSD

tox.ini

@@ -12,7 +12,7 @@ deps = -r{toxinidir}/requirements.txt
 # NOTE: If py35 fails with "db type could not be determined", delete
 # .testrepository and try again. Running py35 before py27 is OK, but not the
 # other way around. See: https://bugs.launchpad.net/testrepository/+bug/1212909
-commands = python setup.py testr --slowest --testr-args="{posargs}"
+commands = stestr run --slowest {posargs}
 
 [testenv:linters]
 commands = yamllint configuration.yaml