Merge "Do not use constraints for venv"

tox.ini

@@ -78,6 +78,10 @@ commands =
   coverage html --include='nova/*' --omit='nova/openstack/common/*' -d covhtml -i
 
 [testenv:venv]
+# NOTE(jaegerandi): This target does not use constraints because
+# upstream infra does not yet support it. Once that's fixed, we can
+# drop the install_command.
+install_command = pip install -U --force-reinstall {opts} {packages}
 commands = {posargs}
 
 [testenv:docs]