RiskManager

- GetOrderSize: add limit_price

risk_manager.go

@@ -9,5 +9,5 @@ type RiskManager interface {
 	GetPnL() (float64, float64)
 	GetProfitRate() float64
 
-	GetOrderSize(symbol string, bid float64) float64
+	GetOrderSize(symbol string, bid float64) (float64, float64)
 }