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: Iddce63084a10cbc5b1670f42acae6c2ee96e0ce8

.gitignore

@@ -7,4 +7,4 @@ build
 *.swp
 *.swo
 *.pyc
-.testrepository
+.stestr/

.stestr.conf

@@ -0,0 +1,4 @@
+[DEFAULT]
+test_path=./tests
+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 ./ . $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

requirements.txt

@@ -4,6 +4,6 @@
 pbr>=0.6,!=0.7,<1.0
 oslosphinx>=2.2.0  # Apache-2.0
 sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
-testrepository>=0.0.18
+stestr>=2.0.0 # Apache-2.0
 testtools>=0.9.36,!=1.2.0
 yasfb>=0.5.1

tox.ini

@@ -10,7 +10,7 @@ usedevelop = True
 setenv = VIRTUAL_ENV={envdir}
 install_command = pip install -U {opts} {packages}
 deps = -r{toxinidir}/requirements.txt
-commands = python setup.py testr --slowest --testr-args='{posargs}'
+commands = stestr run --slowest {posargs}
 
 [testenv:venv]
 commands = {posargs}