migration path drop in file  from 0.4.0 to 1.0.0

while its great to see that there is now a type for drop ins i am missing a migration path from handling drop-in file with systemd::unit_file.
if i ugrade from 0.x to 1.x have to change all of my modules using something like this 

```
systemd::unit_file{'myserviceservice.d/10-disable.conf':
   ...
```

at the same time. otherwise my code breaks at  assert_type(Systemd::Unit, $name)