For Arch, Inspec define `platform[:family]` as `linux` and
`platform[:name]` as `arch`.

* test/integration/default/controls/services_spec.rb: favor modifier
  if usage when having a single-line body.

* test/integration/default/controls/config_spec.rb: add frozen string
  literal comment.

* test/integration/default/controls/packages_spec.rb: ditoo.

* test/integration/default/controls/services_spec.rb: ditoo.

* Refactor `package_name` using `case` like other formulas

* ci(kitchen): use `openssh.config` as `state_top`
* Semi-automated using https://github.com/myii/ssf-formula/pull/33
* test(pillar): remove deprecated option and disabled method
* https://travis-ci.org/myii/openssh-formula/jobs/585340845#L1811-L1813:
* test(pillar): use same SSH options as used by Travis
* Using existing options locks out after `kitchen converge` (before `verify`)
* https://travis-ci.org/myii/openssh-formula/jobs/585356835#L2957-L2965:
* test(inspec): add tests based on existing Serverspec tests
* Follows on from #166