Add futuresMultipleOrders function

Author: Wostafa

node-binance-api.js

@@ -4063,6 +4063,11 @@ let api = function Binance( options = {} ) {
         futuresMarketSell: async ( symbol, quantity, params = {} ) => {
             return futuresOrder( 'SELL', symbol, quantity, false, params );
         },
+        
+        futuresMultipleOrders: async ( orders = [{}] ) => {
+            let params = { batchOrders: JSON.stringify(orders) };
+            return promiseRequest( 'v1/batchOrders', params, { base:fapi, type:'TRADE', method:'POST'} );
+        },
 
         futuresOrder, // side symbol quantity [price] [params]