使用make peer 后protoc-gen-go这个文件找不到的情况
报错：
cp: omitting directory ‘build/docker/gotools/bin/protoc-gen-go’
Makefile:262: recipe for target ‘build/image/ccenv/payload’ failed
解决：
自己安装后拷贝到 build/docker/gotools/bin/ 目录，然后再次执行编译 peer 的命令
cd $GOPATH/src/github.com/golang/
git clone https://git.oschina.net/mellymeng/protobuf.git
go get -u github.com/golang/protobuf/protoc-gen-go
cd $GOPATH
cp bin/protoc-gen-go /opt/gopath/src/github.com/hyperledger/fabric/build/docker/gotools/bin/
方法参考：
https://www.cnblogs.com/chenfool/p/8494052.html
