message: Fixes comment in lookup_ops.py referencing previous contrib location.
diff: @@ -236,9 +236,9 @@ class HashTable(InitializableLookupTableBase):
  Example usage:
  ```python
  - table = tf.contrib.lookup.HashTable(
  - tf.contrib.lookup.KeyValueTensorInitializer(keys, values), -1)
  - out = table.lookup(input_tensor).
  + table = tf.HashTable(
  + tf.KeyValueTensorInitializer(keys, values), -1)
  + out = table.lookup(input_tensor)
  table.init.run()
  print(out.eval())
  ```
  