func equals(k1 string, keys ...string) bool {
	for _, k2 := range keys {
		if strings.EqualFold(k1, k2) {
			return true
		}
	}
	return false
}

// returns replicationAction by comparing metadata between source and target
func getReplicationAction(oi1 ObjectInfo, oi2 minio.ObjectInfo, opType replication.Type) replicationAction {