func (s SagaCoordinator) MakeSaga(sagaId string, job []byte) (*Saga, error) {
	return newSaga(sagaId, job, s.log, s.stat)
}
Make a Saga add it to the SagaCoordinator, if a Saga Already exists
with the same id, it will overwrite the already existing one.
package saga
import (
	log "github.com/sirupsen/logrus"
	"github.com/twitter/scoot/common/stats"
)
type SagaCoordinator struct {
	log  SagaLog
	stat stats.StatsReceiver
}
func MakeSagaCoordinator(log SagaLog, stat stats.StatsReceiver) SagaCoordinator {
	if stat == nil {
		stat = stats.NilStatsReceiver()
	}
	return SagaCoordinator{
		log:  log,
		stat: stat,
	}
}