code: function show(req, res, next) {
    db.users.find(req.params.user, function(err, user) {
      if(err) { return next(err); }
      res.json(user);
    });
  }
docs: URL: /users/:user
  
  Method: GET
  
  Status codes:
  
  * `200` ok
  * `404` not found