Groups Install support

Todo:

- [ ] Test, test, test
- [ ] What do we do with `state=latest`
- [ ] What do we do with `state=removed`

Fixes #1 

Will work a bit more on it in the upcoming days. For now, I would like to know if the approach I am taking would be valid for everyone's use case. 

**Note**

This would mean that "@development" would still fail,  but "@Development Tools" would work. Not perfect, but it would be a good start I think.