[YogaKit] support macOS.

YogaKit/YogaKitSample/YogaKitSample/ViewControllers/BasicViewController.swift

@@ -10,14 +10,11 @@ import YogaKit
 
 final class BasicViewController: UIViewController {
     override func viewDidLoad() {
-        let containerSize = self.view.bounds.size
 
         let root = self.view!
         root.backgroundColor = .white
         root.configureLayout { (layout) in
             layout.isEnabled = true
-            layout.width = YGValue(containerSize.width)
-            layout.height = YGValue(containerSize.height)
             layout.alignItems = .center
             layout.justifyContent = .center
         }

YogaKit/YogaKitSample/YogaKitSample/YogaKitSample.entitlements

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.app-sandbox</key>
+	<true/>
+	<key>com.apple.security.network.client</key>
+	<true/>
+</dict>
+</plist>