Modify rnn op unit test after refactoring framework proto.

Update grad_op_builder after refactoring framework proto.

Step 1: Make code compile well.

"remove type alias"

* init grad op checker

* can run

* add GradeChecker class

* use get_numeric_gradient

* refine code

* add softmax and cross entropy auto grad test

* use close to judge op_grad and numeric_grad

* add cpu and gpu compare

* add comments

* add support_gpu

* fix allclose

* fix name error and symplify code

* optimize gradient checker

* add test_cross_entropy_op

* update gradient_checker.py

* optimize code

* use random.uniform instead of random.random

* fix type bug

* optimize check_grad

* put SupportGPU into OperatorBase

* typo

* Although backward_test/rnn_test is not pass, just comment them.

Add uniform random operator

reduce travis-ci time of build_doc

Add a Kmax sequence score layer.

* remove external_project_dependencies for proto/CMakeLists.txt

Add a nest sequence select layer.

Fix C-API Compilation Error

Update releasing_process.md for pypi upload

* fix some enforce

* remove compatible_type to avoid compile error

* remove shared_ptr

* fix tensor error msg

Remove curl progress info in Dockerfile

Remove wget progress of downloading Go from build log