Replacing deprecated list_hosts with list_hypervisors

The compute os-hosts API is deprecated as of the 2.43 microversion,
and Hypervisors (os-hypervisors) API is recommended to list and
show host details. This is to replace deprecated usage of list_hosts
with list_hypervisors, which is a supplement of
https://review.openstack.org/#/c/552434/

ref: https://developer.openstack.org/api-ref/compute/#list-hosts

Change-Id: Ia02c86c3e3ea658492760b461d7a0349ac69e786
2 files changed