Bugfix: there were services that would get matched because of the way the regex was constructed, i.e. if the user inserted `.` or `*` or anything regexy. Even if the service only had part of the name you were interested in, it would match (e.g. `sshd` would find `my_sshdaemon`).
Apart from this, runlevels are now detected for SystemV. This is exposed in `#info`
NB I've just added default duplicates to one instance (i.e., there's
only one `systemd_service`), since there's no os-specific magic in them.
Also these tests only verify that the default choice is equivalent to
`service` on the tested distribution.
