Updated openstack/openstack
Project: openstack-infra/devstack-gate  b89c850c0537716b96d7c99bf1669d0d3bdf880d
null
Wire up support for DEVSTACK_GATE_SMOKE_SERIAL

We want to default to running smoke tests in parallel, but that won't
work in neutron so add a serial mode that can be explicitly set.

Change-Id: Ia659fd7016458f6ba4d4d43ec5811cd830ddd22d