Merge pull request kodecocodes#765 from chickdan/master

[Swift 4.2] Update Tree

Author: richard-ash

Tree/Tree.playground/Contents.swift

@@ -1,10 +1,5 @@
 //: Playground - noun: a place where people can play
 
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
-
 let tree = TreeNode<String>(value: "beverages")
 
 let hotNode = TreeNode<String>(value: "hot")

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>