title: Module 'tensorflow' has no attribute 'contrib' for the version tensorflow 2.0
body: <p>This issue was raised before as well but the problem persists for me. I am trying to build a 
  training detector model using tensorflow. I will tell whatever I have tried so far :</p>
  
  <ol>
  <li>Replacing tf.contrib with TPUStrategy. Any suggestions on applying this feature on my code will be 
  grateful. (<a href="https://github.com/tensorflow/tensorflow/issues/26513" rel="nofollow noreferrer">https://github.com/tensorflow/tensorflow/issues/26513</a>)</li>
  <li>Tried installing pycocotools for model_main.py</li>
  <li>Instead of "import tensorflow as tf" tried "import tensorflow.compat.v1 as tf"</li>
  <li>Tried replacing "contrib" with "experimental"</li>
  <li>Tried installing tensorflow addons</li>
  </ol>
  
  <p>As per the release notes <a href="https://github.com/tensorflow/tensorflow/releases/tag/v2.0.0-alpha0" rel="nofollow noreferrer">https://github.com/tensorflow/tensorflow/releases/tag/v2.0.0-alpha0</a> , it says 
  tf.contrib has been deprecated, and functionality has been either migrated to the core TensorFlow API, to tensorflow/addons or removed entirely.
  If it is migrated to tensorflow addons, which addon is it?
  I've tried almost everything.
  Tensorflow Version: 2.0</p>
  
  <p>Getting error in the line: </p>
  
  <pre><code>slim_example_decoder = tf.contrib.slim.tfexample_decoder
  </code></pre>
  
  <p>Can anyone provide me with any alternative?</p>