As of change If1e03c9343b8cc9c34bd51c2b4d25acdb21131ff, using
"nova hypervisor-list" before compute hosts are mapped to a cell
will result in an empty list.
Our cells v2 install steps mention using 'nova hypervisor-list' after
creating a cell and starting compute services to tell when to run
the discover_hosts command, but now hypervisor-list won't work until
you've run discover_hosts, so it's a catch-22.
This change adds a release note to let people writing deployment tools
to know about the change in behavior and also updates the install steps
to use service-list instead of hypervisor-list, since service-list does
not require the compute host to be mapped to the cell first.
We are going to need to make a similar change in the OpenStack install
guide since that also mentions using 'nova hypervisor-list' before
discover_hosts.
Change-Id: If2baab40c2e2a3de20e561bba50688d615b002ef
Closes-Bug: #1682060