removeImage method
Remove the image tagged tag.
rig can build images, so it can remove them: a caller that builds one should not have to reach for the Docker CLI to clean it up. Removing a tag that is already gone succeeds — that is the state the caller wanted.
Implementation
@override
Future<void> removeImage(String tag) async {
calls.add('removeImage:$tag');
images.remove(tag);
}