Auditing implicitly unwrapped optionals

Source/Alamofire.swift

@@ -922,7 +922,7 @@ extension Request {
     public class func JSONResponseSerializer(options: NSJSONReadingOptions = .AllowFragments) -> Serializer {
         return { (request, response, data) in
             var serializationError: NSError?
-            let JSON: AnyObject! = NSJSONSerialization.JSONObjectWithData(data!, options: options, error: &serializationError)
+            let JSON: AnyObject? = NSJSONSerialization.JSONObjectWithData(data!, options: options, error: &serializationError)
 
             return (JSON, serializationError)
         }
@@ -945,7 +945,7 @@ extension Request {
     public class func propertyListResponseSerializer(options: NSPropertyListReadOptions = 0) -> Serializer {
         return { (request, response, data) in
             var propertyListSerializationError: NSError?
-            let plist: AnyObject! = NSPropertyListSerialization.propertyListWithData(data!, options: options, format: nil, error: &propertyListSerializationError)
+            let plist: AnyObject? = NSPropertyListSerialization.propertyListWithData(data!, options: options, format: nil, error: &propertyListSerializationError)
 
             return (plist, propertyListSerializationError)
         }