-- internal testing not run correctly, add some dependencies were not caught
-- use synthetic data to run tests (under boolean flag test_small_sample)
-- update class formatting
-- switch all scripts to python3
-- add a formal test for data iterator and one step of training
-- update tensorflow dependencies (as some code is now dependent on tensorflow v1) we should update in a seperate cl to v2
-- general cleanup and improvement to documentation

PiperOrigin-RevId: 275872810