We force the hostname in `kitchen` so the `_mapdata` files can be
static.

We avoid compatibility break with user pillars by looking up
configuration values using `config.get` in configurable roots.

We provide a new parameter `map_jinja:config_get_roots` in the formula
`parameters/defaults.yaml`to retrives values not only from
`tplroot=openssh` but from `sshd_config` and `ssh_config` too.

We need to update the `_mapdata` reference files to include the new
`map_jinja:config_get_roots`.

We store validated `map.jinja` dump under the profile `files`
directory to access them with `inspec.profile.file('filename')` to
validate the content of the generated mapdata file.

The YAML files contain a value specific to each minion, its hostname,
so we use string format to expand `%{hostname}`.

The `default` inspec profile need to depends on `share` to access the
`system` and `salt_minion` libraries.