Add dns-zone-add and dns-zone-delete

dns-zone

@@ -11,6 +11,8 @@ Usage: $SCRIPT [OPTIONS]... COMMAND [COMMAND OPTIONS]
 Manage DNS zones.
 
 Commands:
+ * add             add new zone
+ * delete          delete zone
  * help [COMMAND]  show help message of commands
  * list            show zone content
 
@@ -68,7 +70,7 @@ if [ "$cmd" == "help" ]; then
 fi
 
 case "$cmd" in
-  list)
+  add|delete|list)
     "$SCRIPT_DIR"/dns-zone-$cmd $params "$@"
   ;;
   "")