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

Build failed. https://zuul.opendev.org/t/openstack/buildset/a9cac2ef9b6047c9a108c33f981b2c... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/0df4de67c29248e8b7a99189f9b45615 : FAILURE in 4m 08s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/81806e77f22a4f32b8fa026302e9a95d : FAILURE in 2m 40s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/2e5952a3504e4eb59a0a71e6bd23f5cf : FAILURE in 3m 12s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/49d27c969efd47e6a26366d7853757d3 : FAILURE in 2m 46s