LIMIT_MAKER orders are not supported

[alanimgur]

LIMIT_MAKER orders are not supported by the ValidateLimitOrder function. They are described on the Binance API docs here: https://github.com/binance-exchange/binance-official-api-docs/blob/master/rest-api.md#new-order--trade

(I also don't quite understand the purpose of client side checks like that because they easily get out of sync with the server.)