code: function deleteRules(rulesToDelete, cb) {
      var idsToRemove = _.pluck(rulesToDelete, "_id");
  
      function deleteRule(fieldRuleId, cb1) {
        rulesModel.findByIdAndRemove(fieldRuleId, cb1);
      }
      async.each(idsToRemove, deleteRule, cb);
    }
docs: process any deletes