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.

Change-Id: I793617e042b38aea4cb177b51b6a7ba4a9268f3c

.gitignore

@@ -29,6 +29,7 @@ develop-eggs
 *.DS_Store
 .idea
 .testrepository
+.stestr
 .tox
 .venv
 .*.swp

.stestr.conf

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

.testr.conf

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

doc/source/contributor/dev-quickstart.rst

@@ -103,15 +103,6 @@ name. For example::
     # run the unit tests under py27 and also run the pep8 tests
     tox -epy27 -epep8
 
-.. note::
-    If tests are run under py27 and then run under py35 the following error may occur::
-
-      db type could not be determined
-      ERROR: InvocationError: '/home/ubuntu/ironic/.tox/py35/bin/ostestr'
-
-    To overcome this error remove the file `.testrepository/times.dbm`
-    and then run the py35 test.
-
 You may pass options to the test programs using positional arguments.
 To run a specific unit test, this passes the -r option and desired test
 (regex string) to `os-testr <https://pypi.python.org/pypi/os-testr>`_::

tox.ini

@@ -13,9 +13,7 @@ setenv = VIRTUAL_ENV={envdir}
          PYTHONWARNINGS=default::DeprecationWarning
          TESTS_DIR=./ironic/tests/unit/
 deps = -r{toxinidir}/test-requirements.txt
-whitelist_externals = rm
 commands =
-    rm -f .testrepository/times.dbm
     ostestr {posargs}
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
@@ -44,10 +42,13 @@ commands =
 [testenv:cover]
 setenv = VIRTUAL_ENV={envdir}
          LANGUAGE=en_US
+         PYTHON=coverage run --source ironic --omit='*tests*' --parallel-mode
 commands =
   coverage erase
-  python setup.py testr --coverage --omit='*test*' --testr-args='{posargs}'
-  coverage report --omit='*test*'
+  ostestr {posargs}
+  coverage combine
+  coverage report --omit='*tests*'
+  coverage html -d ./cover --omit='*tests*'
 
 [testenv:checkconfig]
 sitepackages = False