update: test for linear_score_ftrl
update: test for linear_score_ftrl

aksnzhy/xLearn,PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn,aksnzhy/xLearn,PKU-Cloud-Lab/xLearn