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

Build failed. https://zuul.opendev.org/t/openstack/buildset/15506baf14a349c2924723efb3d3b9... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/4ce5e7d44b4040ae801ab83b840a90e9 : SUCCESS in 3m 29s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/8858008b7d3b44a3b4ea2be54f49c389 : FAILURE in 5m 31s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/fe9f829c9e51452dab6b4f649bc71fd7 : SUCCESS in 2m 58s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/92560a7087274788a87926deff07996d : SUCCESS in 4m 19s