Switch to use stestr for unit test

According to Openstack summit session [1],
stestr is maintained project to which all Openstack projects should migrate.
So we should switch to stestr.

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

Change-Id: I6c6e1b3873a71d3b069f0c0bc45d9ba9885c2886

.gitignore

@@ -26,7 +26,7 @@ pip-log.txt
 .coverage
 .tox
 nosetests.xml
-.testrepository
+.stestr/
 .venv
 
 # Translations

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./tempest_horizon/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

test-requirements.txt

@@ -9,6 +9,6 @@ python-subunit>=1.0.0 # Apache-2.0/BSD
 sphinx>=1.6.2 # BSD
 oslosphinx>=4.7.0 # Apache-2.0
 oslotest>=1.10.0 # Apache-2.0
-testrepository>=0.0.18 # Apache-2.0/BSD
+stestr>=2.0.0 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT

tox.ini

@@ -9,7 +9,7 @@ install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/test-requirements.txt
-commands = python setup.py test --slowest --testr-args='{posargs}'
+commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
 basepython = python3
@@ -20,8 +20,14 @@ basepython = python3
 commands = {posargs}
 
 [testenv:cover]
-basepython = python3
-commands = python setup.py test --coverage --testr-args='{posargs}'
+setenv =
+   {[testenv]setenv}
+   PYTHON=coverage run --source tempest_horizon --parallel-mode
+commands =
+   stestr run {posargs}
+   coverage combine
+   coverage html -d cover
+   coverage xml -o cover/coverage.xml
 
 [testenv:docs]
 basepython = python3