title: Module compiled with swift 4.0 cannot be imported in swift 3.1
body: <p>Apparently I have managed to build my project in Xcode 9 beta and now I only get the error</p>
  
  <blockquote>
    <p>Module compiled with swift 4.0 cannot be imported in swift 3.1</p>
  </blockquote>
  
  <p>When I run the project in Xcode 8. The module in my case are Alamofire. I have tried to restart Xcode but nothing happens any ideas how to solve this issue?</p>