* move incubate to geometric

* add paddle.geometric

* fix unittest bug

* add float16 support for segment op

* change reindex and sample neighbors flag name

* add heter graph reindex

* move sample_neighbors.py to neighbors.py

* delete khop_sampler in geometric

* delete unused code

* change sample_neighbors api input order

* fix en doc

* fix unittest

* fix unittest

* change reindex

* fix division by 0

* delete unnecessary input argument

* delete final_state

* 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

* [Eager]Fix segment_pool/allclose/isclose/scale API bug

* fix kernel register problem

* refactor eager flags

* fix flags error when we switch from eager to dygraph

* fix ci problem

* fix ci

* fix ci

* merge develop and fix code style

* merge develop and fix code style

* fix op test error

* fix op test error

* fix op test error

* fix op test error

* fix op test error

* merge develop

* segment pool support for int int64 kernel.

* add support in python api