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

Build failed. https://zuul.opendev.org/t/openstack/buildset/442628b388864db9a0ba0d0d42cf44... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/5eecf548259a4713b84d669d0f61602a : FAILURE in 3m 12s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/5b05703a333742fcb3fb501c5a9d72e4 : FAILURE in 3m 52s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/8d938eaddc264dbba09ea85494104bf1 : FAILURE in 2m 31s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/3b964c5e29014d6e8cefae0f63031d4a : FAILURE in 2m 46s