[Swift 4.2] Update Tree

Author: chickdan

Tree/Tree.playground/Contents.swift

@@ -1,8 +1,8 @@
 //: Playground - noun: a place where people can play
 
 // last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
+#if swift(>=4.2)
+print("Hello, Swift 4.2!")
 #endif
 
 let tree = TreeNode<String>(value: "beverages")

Tree/Tree.playground/contents.xcplayground

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<playground version='5.0' target-platform='osx'>
+<playground version='5.0' target-platform='osx' last-migration='1000'>
     <timeline fileName='timeline.xctimeline'/>
 </playground>