private async Task DeleteInstance(DBInstance instance)
{
_logger.Info("Deleting old instance.");
string finalSnapshotID = $"beta-final-snap-{SystemClock.Instance.GetToday().ToISOString()}-{Guid.NewGuid().ToString()[0]}";
var deleteRequest = new DeleteDBInstanceRequest()
{
DBInstanceIdentifier = instance.DBInstanceIdentifier,
FinalDBSnapshotIdentifier = finalSnapshotID
};
await _rdsClient.DeleteDBInstanceAsync(deleteRequest);
}