go: add go/libct.pb.go in git

Step 19 : RUN go get github.com/avagin/libct/go
 ---> Running in 76a5c8430fae
# github.com/avagin/libct/go
go/src/github.com/avagin/libct/go/libct.go:11: undefined: RpcResponse
2014/05/23 16:18:56 The command [/bin/sh -c go get github.com/avagin/libct/go] returned a non-zero code: 2