* delete old dygraph op test

* isort all files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

* mv eigvalsh op

* 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

* Enhance test_eigh_op

* Use eigen decomposition to validate eigen values and vectors
* Fix that TestEighBatchAPI didn't run the batched input

* Enhance test_eigvalsh_op

* Align cusolver tolerance to validate eigenvalues
* Fix that BatchAPI didn't run the batched input

* Add abs for |d_ref|

* Remove comment

* add eigvalsh with is_test

* add eigvalsh op

* fix backward bug

* forward and backward, float and complex, unittest

* remove eigvalsh_helper.h

* remove changes of cusolver.h

* fix unittest

* fix unittest bug

* update code following eigh

* fix test

* update lapack

* pull develop

* update funcor

* fix unittest bug

* fix details

* add tensor_method_func

* fix notes