fix think.model.mongo is undefined

src/index.js

@@ -258,7 +258,7 @@ export default class {
    */
   loadMVC(){
     let types = {
-      model: ['base', 'relation'],
+      model: ['base', 'relation', 'mongo', 'adv'],
       controller: ['base', 'rest'],
       logic: ['base'],
       service: ['base']

src/model/adv.js

@@ -1,3 +1,8 @@
+'use strict';
+
+/**
+ * adv model
+ */
 export default class extends think.model.base {
 
 }