Additional AdminClient operations.

Fix test

Author: jsantander

tests/test_admin.rs

@@ -973,7 +973,7 @@ async fn test_describe_groups_one_does_not_exist() {
     assert!(result
         .iter()
         .any(|description| if let Ok(description) = description {
-            description.group_id == group_name1 && description.state == ConsumerGroupState::Dead
+            description.group_id == group_name2 && description.state == ConsumerGroupState::Dead
         } else {
             false
         }));