优化工单模块，增加企微模块

sg_wechat_enterprise/we_api/enterprise/exceptions.py

@@ -0,0 +1,9 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import, unicode_literals
+from wechatpy.exceptions import WeChatException
+
+
+class InvalidCorpIdException(WeChatException):
+
+    def __init__(self, errcode=-40005, errmsg='Invalid corp_id'):
+        super(InvalidCorpIdException, self).__init__(errcode, errmsg)