remove 'servicehost' role

* it's unused
* our workflow covers what it's supposed to do
re-format YAML files

* this is like "one-sentence-per-line" :)
Clarify IP space
Merge pull request #17 from seankelly/ip-addr

Clarify IP space
Merge sa2ajj/buildbot-infra:remove-unused-role (PR #15)
Merge sa2ajj/buildbot-infra:formatting (PR #16)