Function to get the time left to asset open

[TheHolsback]

add the following code in stable_api.py

def digital_asset_open_in(ACTIVES):
    data=self.get_digital_underlying_list_data()["underlying"]

    for active in data:
        if active["underlying"]== ACTIVES:
            schedule=active["schedule"]
            for schedule_time in schedule:
                start = schedule_time["open"]
                if start>time.time():
                    time_to_open= start-time.time()
                    #print(time_to_open)
                    break 
            break

    return time_to_open