Load hero details from JSON file into memoy

def load_heroes():
    """
    Load hero details from JSON file into memoy
    """

    filename = os.path.join(os.path.dirname(__file__), "data", "heroes.json")

    with open(filename) as f:
        heroes = json.loads(f.read())["result"]["heroes"]
        for hero in heroes:
            HEROES_CACHE[hero["id"]] = hero