validators example: Update name attribute for zip code field

demo/validators.html

@@ -90,7 +90,7 @@
                             <div class="form-group">
                                 <label class="col-lg-3 control-label">US zip code</label>
                                 <div class="col-lg-3">
-                                    <input type="text" class="form-control" name="usZipCode" />
+                                    <input type="text" class="form-control" name="zipCode" />
                                 </div>
                             </div>
                         </fieldset>