message: Fix the documentation of tf.foldl to not try to fold a scalar.
diff: @@ -91,7 +91,7 @@ def foldl(fn, elems, initializer=None, parallel_iterations=10, back_prop=True,
  Example:
  ```python
  - elems = [1, 2, 3, 4, 5, 6]
  + elems = tf.constant([1, 2, 3, 4, 5, 6])
  sum = foldl(lambda a, x: a + x, elems)
  # sum == 21
  ```
  