* remove paddle.fluid.dygraph.nn.conv2D

* fix ut

* fix conv fp16 UT

* [CodeStyle][py2][U008] remove unnecessary args in `super()`

* remove remained args

* revert changes in test_pylayer_op

* Revert "revert changes in test_pylayer_op"

This reverts commit ff185a9ae738afac3b0264f61bde6c6b7f72e7c4.

* revert some changes in example code

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle][F401] remove unused imports in unittests/dygraph_to_static

* [CodeStyle][F401] remove unused imports in unittests/ir

* add noqa after required imports

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

Add Yolov3 as ProgramTranslator Unit Test. The YoloV3 code is referred from PaddlePaddle/models/dygraph/yolov3