TFX Basic Shared Libraries 1.4.0

Major Features and Improvements

• Introduces RecordBatchToExamplesEncoder that supports encoding nested
  pyarrow.large_list()s representing tf.RaggedTensors.

Bug Fixes and Other Changes

• Register s2t ops before loading decoder in record_to_tensor_tfxio if
  struct2tensor is installed.
• Depends on pyarrow>=1,<6.
• Depends on tensorflow-metadata>=1.4,<1.5.

Breaking Changes

• N/A

Deprecations

• Deprecated python 3.6 support.