message: Add `parallel_interleave` to tf/contrib/data/__init__.py so that it is directly addressable from tf.contrib.data.
diff: @@ -30,6 +30,7 @@ See the @{$datasets$Importing Data} Programmer's Guide for an overview.
  @@make_saveable_from_iterator
  @@read_batch_features
  @@unbatch
  +@@parallel_interleave
  @@rejection_resample
  @@sloppy_interleave
  @@ -50,6 +51,7 @@ from tensorflow.contrib.data.python.ops.dataset_ops import get_single_element
  from tensorflow.contrib.data.python.ops.enumerate_ops import enumerate_dataset
  from tensorflow.contrib.data.python.ops.error_ops import ignore_errors
  from tensorflow.contrib.data.python.ops.grouping import group_by_window
  +from tensorflow.contrib.data.python.ops.interleave_ops import parallel_interleave
  from tensorflow.contrib.data.python.ops.interleave_ops import sloppy_interleave
  from tensorflow.contrib.data.python.ops.iterator_ops import make_saveable_from_iterator
  from tensorflow.contrib.data.python.ops.readers import FixedLengthRecordDataset
  