The DO Community placeholder servers are gone. The file now lists the three
hosts the playbooks address by name -- monoco, clair and emily -- under a `web`
group, with the Python 3 interpreter setting kept as an all-hosts var.
No ansible_host is given for any of them: the control node's ~/.ssh/config
already maps each alias to an address, the same convention
prepare-server/inventory documents. Like that file, this one is only read when
it is named explicitly (`-i hosts`) -- Ansible does not discover an inventory by
name.
tanshu