iOS7 UITextAttributeFont replacement

REMARK

use NSFontAttributeName

for example: change navigation bar title color and font

navigationBar.titleTextAttributes = [
    NSForegroundColorAttributeName: UIColor(red: 90 / 255.0, green: 103 / 255.0, blue: 145 / 255.0, alpha: 1.0),
    NSFontAttributeName: UIFont(name: "Heiti SC", size: 24),
]