1. Masonry权值

http://www.bubuko.com/infodetail-1149793.html

最大值 1000 Masonry默认 UILayoutPriorityDefaultHigh = 750

// 调整label随内容变化的权重
  [label setContentCompressionResistancePriority:UILayoutPriorityDefaultHigh forAxis:UILayoutConstraintAxisHorizontal];