* 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

* rrelu逻辑部分

* unregistered op kernel (unresolved)

* commit before merge

* 丰富测试用例

* 修复rrelu-sig的bug

* 修复cpu环境测试

* 修改拼写错误

* 修改code format

* 尝试优化测试用例timeout的问题

* 优化测试用例

* 移除seed, 优化随机函数

* update en doc for rrelu

* fix rrelu en docs, test=document_fix

* add paper link for en docs, test=document_fix

* udpate en doc

* add r,test=document_fix