code: function(path) {
  
          var _this = this,
              target = PATH.resolve(this.root, this.target, path),
              repo = joinUrlPath(this.url, path);
  
          return QFS.exists(target)
              .then(function(exists) {
  
                  var cmd = exists?
                          _this.getUpdateCmd(repo, target) :
                          _this.getInitialCheckoutCmd(repo, target),
                      d = Q.defer();
  
                  _this.log(cmd);
  
                  CP.exec(cmd, function(err, stdout, stderr) {
                      stdout && _this.log(stdout);
                      stderr && _this.log(stderr);
  
                      if (err) return d.reject(err);
  
                      _this.lastRunTime = Date.now();
                      d.resolve();
                  });
  
                  return d.promise;
  
              });
  
      }
docs: /* jshint +W098 
  Checkout or update single repository path.
  
  @param {String} path  Repository path to checkout / update.
  @return {Promise * Undefined}