Added SG Postal code validator

src/js/validator/zipCode.js

@@ -22,6 +22,7 @@
          * - IT (Italy)
          * - NL (Netherlands)
          * - SE (Sweden)
+         * - SG (Singapore)
          * @returns {Boolean}
          */
         validate: function(validator, $field, options) {
@@ -44,6 +45,7 @@
 
                 case 'SE': return /^(S-)?\d{3}\s?\d{2}$/i.test(value);
                 case 'US':
+                case 'SG': return /^([0][1-9]|[1-6][0-9]|[7]([0-3]|[5-9])|[8][0-2])(\d{4})$/i.test(value);
                 default: return /^\d{4,5}([\-]\d{4})?$/.test(value);
             }
         },