causal conv eager issue keras tensorflow

causal_keras_error.py

import tensorflow as tf
#import keras # works, but wants tf.contrib.eager.Variable for eager execution somewhere
from tensorflow import keras # <- errors on padding='causal'

import numpy as np
#tf.enable_eager_execution() #

data = np.random.random([1,1,256])

leaky_relu = tf.nn.leaky_relu
model = keras.Sequential([
    keras.layers.Conv1D(16, 2, padding='causal', dilation_rate=2, activation=leaky_relu) ])

opt = tf.train.AdamOptimizer()
model.compile(opt, loss = 'mean_squared_error', metrics=['accuracy'])

model.fit(data, y=np.random.random([1,1,16]), batch_size=1)