Merge pull request kodecocodes#321 from raywenderlich/Queue-Naming-Fix

Modified the peek property name to front

Author: kelvinlauKL

Queue/Queue.playground/Contents.swift

@@ -34,7 +34,7 @@ public struct Queue<T> {
     }
   }
 
-  public var peek: T? {
+  public var front: T? {
     return array.first
   }
 }
@@ -56,7 +56,7 @@ queueOfNames.dequeue()
 
 // Return the first element in the queue.
 // Returns "Lisa" since "Carl" was dequeued on the previous line.
-queueOfNames.peek
+queueOfNames.front
 
 // Check to see if the queue is empty.
 // Returns "false" since the queue still has elements in it.

Queue/Queue.playground/timeline.xctimeline

@@ -68,7 +68,7 @@ public struct Queue<T> {
     }
   }
 
-  public func peek() -> T? {
+  public var front: T? {
     return array.first
   }
 }
@@ -166,12 +166,8 @@ public struct Queue<T> {
     return element
   }
 
-  public func peek() -> T? {
-    if isEmpty {
-      return nil
-    } else {
-      return array[head]
-    }
+  public var front: T? {
+    return array.first
   }
 }
 ```