code: function remove(user, callback) {
        var cb = callback || angular.noop;
  
        return User.remove({id: user._id},
          function (user) {
            return cb(user);
          },
          function (err) {
            return cb(err);
          }).$promise;
      }
docs: @ngdoc function
  @name remove
  @methodOf auth.user.service:UserService
  @description
  Remove a user
  
  @param {Object} user The userData to remove
  @param {Function} [callback] A callback
  @return {Promise} A promise