在centos7部署etcd v3的c++客户端

1. wget -c https://cmake.org/files/v3.11/cmake-3.11.2.tar.gz

2.https://github.com/Microsoft/cpprestsdk/wiki/How-to-build-for-Linux

   submodule update --init

1. https://github.com/nokia/etcd-cpp-apiv3