func init() {
	gob.Register(Store{})
	gob.Register(Entry{})
	gob.Register(time.Time{})
}
why?
on the future we may change how these encoders/decoders
and we may need different method for store and other for entry.
package memstore
import (
	"bytes"
	"encoding/gob"
	"io"
	"time"
)