Implement placeOrders() in available wrappers

[Desrever Nu]

/**
     * Places multiple orders, sequencially one-by-one or
     * using a single API entry point when available.
     *
     * @param orders A list of orders to place
     * @param pair   The currency pair of the order.
     * @return an ApiResponse object with a MultipleOrdersResponse with individual responses, ApiError in case
     * of general error.
     */
    public ApiResponse placeOrders(ArrayList<OrderToPlace> orders, CurrencyPair pair);

Make a bitbucket issue for each supported exchange and resolve this once all are resolved

[Desrever Nu]

remember to remove the multipleorders method from OrderManager

[Desrever Nu]

Look at WrapperTestUtils.testPlaceOrders to see how the MultipleOrdersResponse can be used