Added a check to URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL) to ensure that the updater state only gets success if the HTTP response was also success. Otherwise, send an HTTPRequestFailed error to the updater.
This provides an error to handle if the URL is invalid or if there is a server error
URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL)
to ensure that the updater state only gets success if the HTTP response was also success. Otherwise, send anHTTPRequestFailed
error to the updater.