Remove unused variables in model.js

Author: Amir-61

lib/model.js

@@ -12,7 +12,6 @@ module.exports = ModelBaseClass;
  * Module dependencies
  */
 
-var async = require('async');
 var util = require('util');
 var jutil = require('./jutil');
 var List = require('./list');
@@ -22,7 +21,6 @@ var _extend = util._extend;
 var utils = require('./utils');
 var fieldsToArray = utils.fieldsToArray;
 var uuid = require('node-uuid');
-var deprecated = require('depd')('loopback-datasource-juggler');
 
 // Set up an object for quick lookup
 var BASE_TYPES = {