Handle amount in import and display

http/ynab-import.go

@@ -123,7 +123,16 @@ func GetAmount(inflow string, outflow string) (pgtype.Numeric, error) {
 	num := pgtype.Numeric{}
 	err := num.Set(inflow)
 	if err != nil {
-		return num, fmt.Errorf("Could not inflow %s: %w", inflow, err)
+		return num, fmt.Errorf("Could not parse inflow %s: %w", inflow, err)
+	}
+
+	if num.Int.Int64() != 0 {
+		return num, nil
+	}
+
+	err = num.Set("-" + outflow)
+	if err != nil {
+		return num, fmt.Errorf("Could not parse outflow %s: %w", inflow, err)
 	}
 	return num, nil
 }