Vel factory function

def create(model: ModelFactory, discount_factor: float, target_update_frequency: int,
           max_grad_norm: float, double_dqn: bool = False):
    """ Vel factory function """
    return DistributionalDeepQLearning(
        model_factory=model,
        discount_factor=discount_factor,
        double_dqn=double_dqn,
        target_update_frequency=target_update_frequency,
        max_grad_norm=max_grad_norm
    )