Convert concat layer from keras to coreml.

    Parameters
    ----------
    keras_layer: layer
        A keras layer object.

    builder: NeuralNetworkBuilder
        A neural network builder object.

def convert_merge(builder, layer, input_names, output_names, keras_layer):
    """
    Convert concat layer from keras to coreml.

    Parameters
    ----------
    keras_layer: layer
        A keras layer object.

    builder: NeuralNetworkBuilder
        A neural network builder object.
    """
    # Get input and output names
    output_name = output_names[0]

    mode = _get_elementwise_name_from_keras_layer(keras_layer)
    builder.add_elementwise(name = layer, input_names = input_names,
            output_name = output_name, mode = mode)