message: Updating release notes: changing minimum Cudnn supported version and adding tensorrt note.
diff: * Distributed Mutex / CriticalSection added to `tf.contrib.framework.CriticalSection`.
  * Better text processing with `tf.regex_replace`.
  * Easy, efficient sequence input with `tf.contrib.data.bucket_by_sequence_length`
  +* Initial support for `tf.contrib.tensorrt` that enables native TensorRT in
  + TensorFlow.
  ## Bug Fixes and Other Changes
  * Accelerated Linear Algebra (XLA):
  * Support `float16` `dtype` in `tf.linalg.*`.
  * Add `tf.estimator.export.TensorServingInputReceiver` that allows `tf.estimator.Estimator.export_savedmodel` to pass raw tensors to model functions.
  +## Deprecations
  +
  +* TensorFlow 1.7 may be the last time we support cuDNN versions below 6.0.
  + Starting with TensorFlow 1.8 release, 6.0 will be the minimum supported
  + version.
  +
  ## Thanks to our Contributors
  This release contains contributions from many people at Google, as well as:
  