Removed an unused 'priority' parameter

Source/Alamofire.swift

@@ -618,14 +618,13 @@ public class Request {
     /**
         Adds a handler to be called once the request has finished.
 
-        :param: priority The dispatch priority / quality of service used to process the response handler. `DISPATCH_QUEUE_PRIORITY_DEFAULT` by default.
         :param: queue The queue on which the completion handler is dispatched.
         :param: serializer The closure responsible for serializing the request, response, and data.
         :param: completionHandler The code to be executed once the request has finished.
 
         :returns: The request.
     */
-    public func response(priority: Int = DISPATCH_QUEUE_PRIORITY_DEFAULT, queue: dispatch_queue_t? = nil, serializer: Serializer, completionHandler: (NSURLRequest, NSHTTPURLResponse?, AnyObject?, NSError?) -> Void) -> Self {
+    public func response(queue: dispatch_queue_t? = nil, serializer: Serializer, completionHandler: (NSURLRequest, NSHTTPURLResponse?, AnyObject?, NSError?) -> Void) -> Self {
         let delegate = self.delegate
         dispatch_async(delegate.queue) { [weak delegate] in
             let (responseObject: AnyObject?, serializationError: NSError?) = serializer(self.request, self.response, delegate?.data)