text: (function() {
    'use strict';
  
    var mongoose = require('mongoose');
    var Schema = mongoose.Schema;
  
    var RoleSchema = new Schema({
      title: {
        type: String,
        required: true,
        index: {
          unique: true
        },
        enum: ['admin', 'contributor', 'viewer', 'administrator']
      }
    });
  
    module.exports = mongoose.model('Role', RoleSchema);
  })();
  