Migrate to stestr as unit tests runner

Recent update brought os-testr 1.0.0 that already uses stestr test
runner instead of testrepository. This patch migrates those places
using testrepository to using stestr.

Inspired by the patch of the same name in openstack/ironic

Change-Id: I49bd08a402663bfabe1fea14957435ee071145e7

.gitignore

@@ -23,6 +23,7 @@ develop-eggs
 
 # Other
 *.DS_Store
+.stestr
 .testrepository
 .tox
 .venv

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=${TESTS_DIR:-./ironic_lib/tests}
+top_dir=./

.testr.conf

@@ -1,10 +0,0 @@
-[DEFAULT]
-test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} \
-             OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} \
-             OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1} \
-             OS_TEST_TIMEOUT=${OS_TEST_TIMEOUT:-60} \
-             OS_DEBUG=${OS_DEBUG:-0} \
-             ${PYTHON:-python} -m subunit.run discover -t ./ $LISTOPT $IDOPTION
-
-test_id_option=--load-list $IDFILE
-test_list_option=--list

tox.ini

@@ -36,8 +36,13 @@ commands =
 [testenv:cover]
 setenv = VIRTUALENV={envdir}
          LANGUAGE=en_US
+         PYTHON=coverage run --source ironic_lib --omit='*tests*' --parallel-mode
 commands =
-  python setup.py test --coverage --coverage-package-name=ironic_lib --omit=ironic_lib/openstack/common/*.py {posargs}
+  coverage erase
+  ostestr {posargs}
+  coverage combine
+  coverage report --omit='*tests*'
+  coverage html -d ./cover --omit='*tests*'
 
 [testenv:venv]
 commands = {posargs}