adapt to stestr 4.0 release

This change removes usage of --black-regex which is no longer supported
as of stestr 4.0.0. The min version of stestr is increased to 3.1.0
which adds --exclude-regex as a replacement.

Change-Id: I24424aeeb178fd9ab1b736cb689a73f7bd8bd572

test-requirements.txt

@@ -5,5 +5,5 @@
 coverage!=4.4,>=4.0 # Apache-2.0
 oslotest>=1.10.0 # Apache-2.0
 ovs>=2.9.2
-stestr>=1.0.0 # Apache-2.0
+stestr>=3.1.0 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD

tox.ini

@@ -12,14 +12,14 @@ deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
-commands = stestr run --black-regex ".tests.functional" {posargs}
+commands = stestr run --exclude-regex ".tests.functional" {posargs}
 
 [testenv:functional]
 envdir = {toxworkdir}/shared
 setenv =
   {[testenv]setenv}
 commands =
-  stestr run --black-regex ".tests.unit" {posargs}
+  stestr run --exclude-regex ".tests.unit" {posargs}
 
 [testenv:docs]
 deps =
@@ -55,7 +55,7 @@ setenv =
   {[testenv]setenv}
   PYTHON=coverage run --source os_vif,vif_plug_linux_bridge,vif_plug_ovs,vif_plug_noop --parallel-mode
 commands =
-  stestr run --black-regex ".tests.functional" {posargs}
+  stestr run --exclude-regex ".tests.functional" {posargs}
   coverage combine
   coverage html -d cover
   coverage xml -o cover/coverage.xml