Init script depends on package if managed

The init script needs to require the package if the packaged is maintained by the module. Otherwise the following error is issued:

```
Error: /Stage[main]/Mariadb/Service[mysql]: Could not evaluate: Could not find i
nit script for 'mysql'
```

PS: I tried to match your coding style. I'm sure there is a better solution regarding DRY, but I'm not very familiar with Ruby/Puppet.