Update to unique_ptr version of API

#include <glog/logging.h>

#include <sys/fcntl.h>

#include <sys/mman.h>

#include <memory>

#include "protobufutil/message_stream.h"

class TestCallback : public GetCallbackInterface {

public:

    TestCallback(char* buffer, unsigned int expected_length, int* remaining) : buffer_(buffer), expected_length_(expected_length), remaining_(remaining) {};

    void Success(const std::string &key, KineticRecord* record) {

    void Success(const std::string &key, std::unique_ptr<KineticRecord> record) {

        if(expected_length_ != record->value().size()) {

            printf("Received value chunk of wrong size\n");

            exit(1);