Updated syntax for 3.7.3 (#7)

* Updated syntax for 3.7.3

The original example won't compile because computed properties can't have willSet/didSet. Also setting a computed property in its own setter throws a warning. This new code will compile (except for the someBool part)

* Update README.md

README.md

@@ -4,7 +4,7 @@ Make sure to read [Apple's API Design Guidelines](https://swift.org/documentatio
 
 Specifics from these guidelines + additional remarks are mentioned below.
 
-This guide was last updated for Swift 2.2 on August 31st, 2016.
+This guide was last updated for Swift 2.2 on September 27th, 2016.
 
 ## Table Of Contents
 
@@ -631,21 +631,24 @@ var computedProperty: String {
 * **3.7.3** Though you can create a custom name for the new or old value for `willSet`/`didSet` and `set`, use the standard `newValue`/`oldValue` identifiers that are provided by default.
 
 ```swift
-var computedProperty: String {
+var storedProperty: String = "I'm selling these fine leather jackets." {
+    willSet {
+        print("will set to \(newValue)")
+    }
+    didSet {
+        print("did set from \(oldValue) to \(storedProperty)")
+    }
+}
+
+var computedProperty: String  {
     get {
         if someBool {
             return "I'm a mighty pirate!"
         }
-        return "I'm selling these fine leather jackets."
+        return storedProperty
     }
     set {
-        computedProperty = newValue
-    }
-    willSet {
-        print("will set to \(newValue)")
-    }
-    didSet {
-        print("did set from \(oldValue) to \(newValue)")
+        storedProperty = newValue
     }
 }
 ```