Delete command

[luisdavim]

It would be nice if in addition to the get command, there was a delete command as well.

[yolken]

Delete functionality was deliberately kept out of the initial version for safety purposes. But, if someone wants to add it now (with sufficient protections), then I'd be open to it.

[a-shchupakov]

It would be nice if there was an option --delete-missing-topics in apply command, which will delete topics that are not present in passed config

[petedannemann]

This was started here #100