“734a9eeaa464510de1374c196e40325efd2f8edb”上不存在“python/paddle/v2/fluid/tests/test_sign_op.py”
* Chage `IndicateDataType` to `GetKernelType`. Make it easier to understand. * Change `OpKernelKey` to `OpKernelType` * Make operator developers can customize which kernel the operator will use in runtime.