Merge pull request kodecocodes#829 from iillx/counting-sort

[Swift 4.2] Counting Sort

Author: richard-ash

Counting Sort/CountingSort.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
-
 enum CountingSortError: Error {
   case arrayEmpty
 }