firstBaseline issue

[Jerryshen170918]

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Issue Info

Info	Value
Platform	e.g. ios/osx/tvos
Platform Version	e.g. 9.0
Masonry Version	e.g. 1.1.0
Integration Method	e.g. carthage/cocoapods/manually

Issue Description

when I study MASExampleLabelView Demo,I find they are some: make.firstBaseline.equalTo(self.longLabel.lastBaseline); make.lastBaseline.equalTo(self.longLabel.lastBaseline); ⚠️ Replace this with the description of your issue. ⚠️