fix compile doc for trt

fix param name

2.0 develop first commit

Update pip version

Update  pip install paddle-serving-app==0.2.0

原命令：pip install paddle-serving-server-gpu==0.4.0.trt # GPU with CUDA10.1+TensorRT

新命令：pip install paddle-serving-server-gpu==0.4.0.100 # GPU with CUDA10.1+TensorRT

fix grpc impl, sync with brpc

[WIP] 2.0 Inference API

fix gbk in win

Fix Readme 0.4

Update README.md