[Openstack-stable-maint] Stable check of openstack/futurist for ref refs/heads/stable/train failed

Build failed. https://zuul.opendev.org/t/openstack/buildset/d63f47f8bcef474c8cfa5a161428cb... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/3b8312258c5143e0935e6e87c3b20732 : FAILURE in 3m 56s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/2719706357b642c5a3b5dd9ac9b1e913 : FAILURE in 2m 51s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/ffb36a2f6a3e4e88a11e95a8897524d1 : FAILURE in 2m 50s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/a514b4278c8044f1a6529badcd32eb8e : FAILURE in 3m 23s