Add support for removal/uninstall?

[uhlhosting]

Hi,

Lovely to have this feature in ApisCP, I just noticed that the notes on it, speak nothing of uninstalling it. Can you add something similar like the steps used in DQS to remove it.

ansible-playbook addin.yml --extra-vars=addin=rspamd-dqs --tags=uninstall,all
rm -rf addins/rspamd-dqs```

[anatolinicolae]

For sure, you can easily implement that addin's logic and submit a PR.