将MLHorizontalLayout添加到项目中
初始化CollectionViewFlowLayout
MLHorizontalCollectionViewFlowLayout *layout = [[MLHorizontalCollectionViewFlowLayout alloc]init];
layout.horizonalType = MLHorizonalLeft;//左对齐
layout.minimumInteritemSpacing = 5.0;
layout.sectionInset = UIEdgeInsetsMake(20.0, 10.0, 20.0, 10.0);