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: I2c1b271550629437627f3f62b6f33e2beb2b3c4b

.gitignore

@@ -10,6 +10,7 @@ devenv/*
 cover
 .coverage
 coverage.xml
+.stestr
 .testrepository
 imagebuild/.image_cache
 imagebuild/coreos/build

.stestr.conf

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

.testr.conf

@@ -1,4 +0,0 @@
-[DEFAULT] 
-test_command=OS_STDOUT_CAPTURE=1 OS_STDERR_CAPTURE=1 OS_TEST_TIMEOUT=60 ${PYTHON:-python} -m subunit.run discover -t ./ ${OS_TEST_PATH:-./ironic_python_agent/tests} $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE 
-test_list_option=--list

tox.ini

@@ -36,8 +36,13 @@ commands =
 
 [testenv:cover]
 setenv = VIRTUAL_ENV={envdir}
+         PYTHON=coverage run --source ironic_python_agent --omit='*tests*' --parallel-mode
 commands =
-  python setup.py test --coverage --coverage-package-name ironic_python_agent {posargs}
+  coverage erase
+  ostestr {posargs}
+  coverage combine
+  coverage report --omit='*tests*'
+  coverage html -d ./cover --omit='*tests*'
 
 [testenv:venv]
 setenv = PYTHONHASHSEED=0