* 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 tril_indices cpu kernal

* modify tril_indice cpu op

* modify bug

* modify bug

* add tril_indices python api

* add tril_indices python api

* resolve conflict

* add tril_indices test

* modify details

* add tril_indices.cu

* pythonapi pass

* save tril_indices

* CPU tril_indices pass

* delete vlog

* modify test_tril_indices_op.py

* delete tril_indices_kernel.cc.swp

* delete tril_indice.cu

* modify code style

* add newline in creation.py

* modify creation.py linux newline

* delete annotation

* check code style

* check .py style add final_state??

* modify code style

* add gpu_tril_indices

* modify gpu_compiled_juage

* modify gpu judge

* code style

* add test example

* modify english document

modify english document

modify english document

modify document

modify document

* modify pram name

* modify pram name

* modify pram

* reduce test ex