Fractional share orders must be Day orders

[jc-gomes]

Right now when ordering fractional shares, the OrdersEndpoint (requestFractionalMarketOrder function) executes with a OrderTimeForce.GOOD_UNTIL_CANCELLED, this fails with status code 422 and response message specifying all fractional orders must be DAY orders. This will need to be fixed so that the order executes as a DAY order.