removed obsolete API ping method

Fixes: #790

Breaking change: Removing obsolete API method Ping.
Ping has been added in the beginning for testing purposes.
It is not needed anymore and, therefore, is removed. Since
it was not even documented in the API spec, its impact is
even less.

Signed-off-by: Michael Engel <mengel@redhat.com>

src/controller/controller.c

@@ -440,22 +440,6 @@ static bool controller_setup_node_connection_handler(Controller *controller) {
         return true;
 }
 
-/************************************************************************
- ****** org.eclipse.bluechi.Controller.Ping ******************
- ************************************************************************/
-
-/* This is a test method for now, it just returns what you passed */
-static int controller_method_ping(sd_bus_message *m, UNUSED void *userdata, UNUSED sd_bus_error *ret_error) {
-        const char *arg = NULL;
-
-        int r = sd_bus_message_read(m, "s", &arg);
-        if (r < 0) {
-                return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Invalid arguments");
-        }
-        return sd_bus_reply_method_return(m, "s", arg);
-}
-
-
 /************************************************************************
  ************** org.eclipse.bluechi.Controller.ListUnits *****
  ************************************************************************/
@@ -944,7 +928,6 @@ static int controller_property_get_log_target(
 
 static const sd_bus_vtable controller_vtable[] = {
         SD_BUS_VTABLE_START(0),
-        SD_BUS_METHOD("Ping", "s", "s", controller_method_ping, 0),
         SD_BUS_METHOD("ListUnits", "", NODE_AND_UNIT_INFO_STRUCT_ARRAY_TYPESTRING, controller_method_list_units, 0),
         SD_BUS_METHOD("ListNodes", "", "a(sos)", controller_method_list_nodes, 0),
         SD_BUS_METHOD("GetNode", "s", "o", controller_method_get_node, 0),