Created by: luotao1

Add version.txt and CMakeCache.txt in inference_lib for version management. The result is:

$ tree -L 1 PaddleRoot/
PaddleRoot/
├── CMakeCache.txt
├── paddle
├── third_party
└── version.txt

The context of version.txt is:

[] -> $ cat PaddleRoot/version.txt
GIT COMMIT ID: ebefdbe372e6d1a87a9eae691d579156c1ce6680
WITH_MKL: ON
WITH_GPU: ON
CUDA version: 8.0
CUDNN version: v7