def train_model(model, train_data, train_targets, epochs):
    """
    This function should train the model for the given number of epochs on the 
    train_data and train_targets. 
    Your function should return the training history, as returned by model.fit.
    """
    return model.fit(train_data, train_targets, epochs = epochs, batch_size = 40, validation_split=0.15, verbose = False)