add puppet to the list of ignored names to allow for a per suite puppet ...

...test configuration

otherwise it fails with at the busser install step:

```
sudo -E ${gem_bindir}/busser setup; sudo -E /tmp/busser/bin/busser plugin install busser-puppet busser-serverspec']
```

I created a workaround with a fake gem https://rubygems.org/gems/busser-puppet
And I think this should be somehow configurable, but can't think of how ...