[TEST] enable pre-commit

[luotao1]

DO NOT MERGE.

[luotao1]

travis-ci上的cpplint没起作用。在05241a0 中删去一个string头文件后，本地效果为

CRLF end-lines remover...............................(no files to check)Skipped
yapf.................................................(no files to check)Skipped
Check for added large files..............................................Passed
Check for merge conflicts................................................Passed
Check for broken symlinks................................................Passed
Detect Private Key...................................(no files to check)Skipped
Fix End of Files.........................................................Passed
clang-format.............................................................Passed
cpplint..................................................................Failed
hookid: cpplint-cpp-source

Ignoring .travis.yml; not a valid file name (c, cc, h, hpp, c++, h++, cu, cpp, hxx, cxx, cuh)
Done processing .travis.yml
paddle/fluid/framework/async_executor.h:90:  Add #include <string> for string  [build/include_what_you_use] [4]
Done processing paddle/fluid/framework/async_executor.h
Total errors found: 1

pylint...............................................(no files to check)Skipped
go fmt...............................................(no files to check)Skipped
copyright_checker........................................................Passed

但travis-ci能过，https://travis-ci.org/PaddlePaddle/Paddle/builds/496920263#L782。
初步怀疑cpplint没装对。

[luotao1]

c9edb61 已经能正确查出所有cpplint的错误。travis-ci跑一遍时间为10分钟，时间上是可以接受的。 @dzhwinter @tianshuo78520a
暴露的错误非常多，比如

paddle/fluid/operators/mul_op.cc:135:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/mul_op.cc:169:  Add #include <memory> for unique_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_bridge.cc:34:  Add #include <memory> for shared_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_bridge.h:43:  Add #include <memory> for shared_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_engine.cc:197:  Add #include <utility> for move  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_engine.cc:291:  Add #include <unordered_set> for unordered_set<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_engine.cc:456:  Add #include <memory> for shared_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_engine.h:0:  No #ifndef header guard found, suggested CPP variable is: PADDLE_FLUID_OPERATORS_NGRAPH_NGRAPH_ENGINE_H_  [build/header_guard] [5]
paddle/fluid/operators/ngraph/ngraph_engine.h:57:  Add #include <unordered_set> for unordered_set<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ngraph_engine.h:81:  Add #include <memory> for shared_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/accuracy_op.h:30:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/accuracy_op.h:58:  Add #include <memory> for make_shared<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/activation_op.h:41:  Add #include <memory> for shared_ptr<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/activation_op.h:41:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/batch_norm_op.h:98:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/batch_norm_op.h:143:  Add #include <memory> for make_shared<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/binary_unary_op.h:42:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/binary_unary_op.h:45:  Add #include <memory> for make_shared<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/conv2d_op.h:192:  Add #include <unordered_map> for unordered_map<>  [build/include_what_you_use] [4]
paddle/fluid/operators/ngraph/ops/conv2d_op.h:220:  Add #include <memory> for make_shared<>  [build/include_what_you_use] [4]

https://travis-ci.org/PaddlePaddle/Paddle/builds/496983517#L5464

pylint应该有同样问题。 @gongweibao