in call.
*   New ops and improved op functionality
    *   Add OpKernels for some stateless maps
    *   Add v2 APIs for AUCCurve and AUCSummationMethod
        enums. #tf-metrics-convergence
    *   Add tf.math.nextafter op.
    *   Add CompositeTensor base class.
    *   Add tf.linalg.tridiagonal_solve op.
    *   Add opkernel templates for common table operations.
    *   Added support for TFLite in TensorFlow 2.0.