title: Alamofire compiled with older version of Swift language (2.0) than previous files (3.0) for architecture x86_64
body: <p>When I move my program to the XCode8, I got this error: Alamofire compiled with older version of Swift language (2.0) than previous files (3.0) for architecture x86_64.
  I have update Alamofire to version 4.0, and set the Use Legacy Swift Language Version to NO.
  What's the matter?</p>