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

Depends-On: https://review.openstack.org/#/c/589728/
Change-Id: I943a73e22eb23bd52c3a96e75c98b88665474e67

.gitignore

@@ -28,7 +28,7 @@ pip-log.txt
 nosetests.xml
 .venv
 cover
-.testrepository
+.stestr/
 htmlcov
 
 # Translations

.stestr.conf

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

.testr.conf

@@ -1,11 +0,0 @@
-[DEFAULT]
-test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} \
-             OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} \
-             OS_TEST_TIMEOUT=${OS_TEST_TIMEOUT:-160} \
-             OS_DEBUG=${OS_DEBUG:-TRACE} \
-             OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1} \
-             ${PYTHON:-python} -m subunit.run discover -t ./ ./taskflow/tests $LISTOPT $IDOPTION
-
-test_id_option=--load-list $IDFILE
-test_list_option=--list
-

lower-constraints.txt

@@ -70,7 +70,7 @@ SQLAlchemy-Utils==0.30.11
 SQLAlchemy==1.0.10
 stevedore==1.20.0
 tenacity==4.4.0
-testrepository==0.0.18
+stestr==2.0.0
 testscenarios==0.4
 testtools==2.2.0
 traceback2==1.4.0

requirements.txt

@@ -47,3 +47,6 @@ cachetools>=2.0.0 # MIT License
 
 # For deprecation of things
 debtcollector>=1.2.0 # Apache-2.0
+
+# For stestr
+stestr>=2.0.0 # Apache-2.0

test-requirements.txt

@@ -29,6 +29,6 @@ oslotest>=3.2.0 # Apache-2.0
 mock>=2.0.0 # BSD
 testtools>=2.2.0 # MIT
 testscenarios>=0.4 # Apache-2.0/BSD
-testrepository>=0.0.18 # Apache-2.0/BSD
+stestr>=2.0.0 # Apache-2.0
 doc8>=0.6.0 # Apache-2.0
 sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD

tox.ini

@@ -21,7 +21,7 @@ deps =
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 commands =
-  python setup.py testr --slowest --testr-args='{posargs}'
+  stestr run {posargs}
 
 [testenv:docs]
 basepython = python3
@@ -56,7 +56,14 @@ basepython = python3
 deps =
   {[testenv]deps}
   coverage>=3.6
-commands = python setup.py testr --coverage --testr-args='{posargs}'
+setenv =
+   {[testenv]setenv}
+   PYTHON=coverage run --source taskflow --parallel-mode
+commands =
+   stestr run {posargs}
+   coverage combine
+   coverage html -d cover
+   coverage xml -o cover/coverage.xml
 
 [testenv:venv]
 basepython = python3