Add default 'puppetservice' name for Unix hosts.

Instead of hard-coding 'pe-httpd' and then only "bounce_service"ing if the
Beaker type is 'pe', add fall-through case if 'puppetservice' key is
defined/nonempty on the host.

Signed-off-by: Wayne <wayne@puppetlabs.com>
Fix rspec to accomodate arbitrary 'puppetservice'

Signed-off-by: Wayne <wayne@puppetlabs.com>
Remove unnecessary conditional and empty string.

Signed-off-by: Wayne <wayne@puppetlabs.com>
Add default 'puppetservice' value for windows.

Signed-off-by: Wayne <wayne@puppetlabs.com>