code: function uploadFile(file, next) {
      var uploadErr;
  
      self.uploadFile({
        source: file.source,
        target: file.target,
        server: options.server,
        keys: options.keys,
        tunnel: options.tunnel,
        remoteUser: options.remoteUser
      }).on('error', function (err) {
        if (!uploadErr) {
          uploadErr = true;
          next(err);
        }
      }).on('complete', function () {
        if (!uploadErr) {
          next();
        }
      });
    }
docs: Helper function which uploads files of the form:  { target: '/full/remote/path/to/upload/to', source: '/full/local/path/to/upload/from' }