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: Ib7b19bed1a16c0864068066fdb5b9e45595dd228

.gitignore

@@ -20,7 +20,6 @@ develop-eggs/
 .tox
 AUTHORS
 ChangeLog
-.testrepository
 .stestr
 .coverage
 cover

.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:-120} \
-             ${PYTHON:-python} -m subunit.run discover $DISCOVER_DIRECTORY $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

lower-constraints.txt

@@ -125,7 +125,6 @@ stevedore==1.28.0
 sympy==1.1.1
 Tempita==0.5.2
 tenacity==4.9.0
-testrepository==0.0.20
 testresources==2.0.1
 testscenarios==0.5.0
 testtools==2.3.0

test-requirements.txt

@@ -7,7 +7,6 @@ coverage>=4.5.1 # Apache-2.0
 python-subunit>=1.2.0 # Apache-2.0/BSD
 oslotest>=3.3.0 # Apache-2.0
 requests-mock>=1.4.0 # Apache-2.0
-testrepository>=0.0.20 # Apache-2.0/BSD
 testscenarios>=0.5.0 # Apache-2.0/BSD
 testtools>=2.3.0 # MIT
 stestr>=2.0.0 # Apache-2.0

tox.ini

@@ -9,8 +9,6 @@ install_command = pip install -U -c{env:UPPER_CONSTRAINTS_FILE:https://git.opens
 whitelist_externals = find
 setenv =
    VIRTUAL_ENV={envdir}
-   OS_TEST_PATH=vitrage/tests/unit
-   DISCOVER_DIRECTORY=vitrage/tests
 deps = -r{toxinidir}/test-requirements.txt
 commands =
     stestr run --serial '{posargs}'
@@ -42,8 +40,13 @@ commands = {posargs}
 
 [testenv:cover]
 basepython = python3
+setenv =
+    PYTHON=coverage run --source $project --parallel-mode
 commands =
-    python setup.py testr --coverage --testr-args='{posargs}'
+    stestr run '{posargs}'
+    coverage combine
+    coverage html -d cover
+    coverage xml -o cover/coverage.xml
     coverage report
 
 [testenv:docs]