Update node-binance-api.js

Handling 'balanceUpdate' event

Author: maxah

node-binance-api.js

@@ -2076,7 +2076,7 @@ let api = function Binance( options = {} ) {
             if ( Binance.options.margin_execution_callback ) Binance.options.margin_execution_callback( data );
         } else if ( type === 'listStatus' ) {
             if ( Binance.options.margin_list_status_callback ) Binance.options.margin_list_status_callback( data );
-        } else if ( type === 'outboundAccountPosition' ) {
+        } else if ( type === 'outboundAccountPosition' || type === 'balanceUpdate') {
             Binance.options.margin_balance_callback( data );
         } else {
             Binance.options.log( 'Unexpected userMarginData: ' + type );