Issue #671

Use adjustsFontForContentSizeCategory

A Boolean that indicates whether the object automatically updates its font when the device’s content size category changes.

If you set this property to YES, the element adjusts for a new content size category on a UIContentSizeCategoryDidChangeNotification.

button.titleLabel?.adjustsFontForContentSizeCategory = true
button.backgroundColor = UIColor.green
button.titleLabel?.font = UIFont.preferredFont(forTextStyle: .title1)

label.adjustsFontForContentSizeCategory = true
label.backgroundColor = UIColor.yellow
label.font = UIFont.preferredFont(forTextStyle: .title1)

However it seems view (UIButton or UILabel) size is the same, just the inner text increases in size. A workaround is to put view inside UIStackView so UIButton or UILabel can automatically changes size.