Switch to use stestr for unit tests directly

This commit switches to use stestr command to run unit tests directly.
Recently, the latest ostestr command uses stestr instead of testr.
However, we should use stestr directly because it's simple and
straight forward. There is no reason to use ostestr for unit tests
anymore.

Modeled after Iff4abef50178bdc83b868eed4a906e22d790762b

Change-Id: Ie50cd57e87bc049c29b86fce67cc1a2061dad690

.gitignore

@@ -59,4 +59,4 @@ ChangeLog
 releasenotes/build
 
 # Misc
-.stestr/
+.stestr

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./patrole_tempest_plugin/tests/unit
+group_regex=([^\.]*\.)*

.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 ./ ${OS_TEST_PATH:-./patrole_tempest_plugin/tests/unit} $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

tox.ini

@@ -12,13 +12,13 @@ setenv =
    LANGUAGE=en_US
    LC_ALL=en_US.utf-8
    PYTHONWARNINGS=default::DeprecationWarning
-passenv = OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_TEST_TIMEOUT OS_TEST_LOCK_PATH OS_TEST_PATH http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+passenv = OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_TEST_TIMEOUT OS_TEST_LOCK_PATH http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 whitelist_externals = find
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
     find . -type f -name "*.pyc" -delete
-    ostestr {posargs}
+    stestr --test-path ./patrole_tempest_plugin/tests/unit run {posargs}
 
 [testenv:pep8]
 commands = flake8 {posargs}