The dependent tempest change enables the volume multiattach
tests in the tempest-full and tempest-slow jobs, on which
nova already gates, which allows us to drop the special
nova-multiattach job which is mostly redundant test coverage
of the other tempest.api.compute.* tests, and allows us to
run one fewer job on nova/cinder/tempest changes in Stein.
The docs are updated to reflect the source of the testing
now.
Also depends on cinder dropping its usage of the nova-multiattach
job before we can drop the job definition from nova.
Depends-On: https://review.openstack.org/606978
Depends-On: https://review.openstack.org/606985
Change-Id: I744afa1df9a6ed8e0eba4310b20c33755ce1ba88
e9dd8c0f48