Merge "Cap tox != 2.8.0 temporarily to avoid ValueError"

Author: Jenkins

lib/tempest

@@ -613,7 +613,7 @@ function configure_tempest {
 # install_tempest() - Collect source and prepare
 function install_tempest {
     git_clone $TEMPEST_REPO $TEMPEST_DIR $TEMPEST_BRANCH
-    pip_install tox
+    pip_install 'tox!=2.8.0'
     pushd $TEMPEST_DIR
     tox -r --notest -efull
     # NOTE(mtreinish) Respect constraints in the tempest full venv, things that