title: Tensorflow Backend - Bug in "model._make_predict_function"
body: <p>there's is a bug while running the Tensorflow code, the error code appears like this:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;app.py&quot;, line 76, in &lt;module&gt;
      model = deepmoji_emojis(maxlen, PRETRAINED_PATH)
    File &quot;/home/lifeofpy/LifeofPy/AI Photographer Project/Text-to-Color/deepmoji/model_def.py&quot;, line 35, in deepmoji_emojis
      model._make_predict_function()
  AttributeError: 'Functional' object has no attribute '_make_predict_function
  </code></pre>
  <p>and the file <strong>app.py</strong> is like this:</p>
  <pre><code># print('Loading model from {}.'.format(PRETRAINED_PATH))
  model = deepmoji_emojis(maxlen, PRETRAINED_PATH)
  model.summary()
  model._make_predict_function()
  </code></pre>
  <p>I think the error message is occured by the function 'model._make_predict_function',
  I would appreciate any comments on this issue. Thanks!</p>