title: pycharm can't complete remote interpreter setup for Docker
body: <p>I'm new to Docker. I'm using Docker &amp; docker-compose, going through a flask tutorial. The base docker image is python 2.7 slim. 
  It's running on Linux. docker 1.11.2
  The application is working fine. 
  I want to get pycharm pro connecting to the remote interpreter, something I have never done before. </p>
  
  <p>I followed the instructions for docker-compose. Initially it was failing because it could not connect to port 2376. I added this port to docker-compose.yml and the error went away. 
  However, trying to save the configuration now stalls/hangs with a dialog 'Getting Remote Interpreter Version'. This never completes. Also, I can't quit pycharm. This happens in Pycharm 2016.2 and 2016.3 EAP (2nd). </p>
  
  <p>The help say "SFTP support is required for copying helpers to the server". 
  Does this mean I need to do something? </p>