优化工单模块，增加企微模块

sg_wechat_enterprise/we_api/client/api/merchant/stock.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import, unicode_literals
+from wechatpy.client.api.base import BaseWeChatAPI
+
+
+class MerchantStock(BaseWeChatAPI):
+
+    def add(self, product_id, quantity, sku_info=''):
+        return self._post(
+            'merchant/stock/add',
+            data={
+                'product_id': product_id,
+                'quantity': quantity,
+                'sku_info': sku_info
+            }
+        )
+
+    def reduce(self, product_id, quantity, sku_info=''):
+        return self._post(
+            'merchant/stock/reduce',
+            data={
+                'product_id': product_id,
+                'quantity': quantity,
+                'sku_info': sku_info
+            }
+        )