Merge pull request yutiansut#1533 from kite8/master

修复base_datastruct中date方法引起的复权问题

Author: yutiansut

QUANTAXIS/QAData/base_datastruct.py

@@ -385,8 +385,8 @@ def position(self):
     def date(self):
         index = self.data.index.remove_unused_levels()
         try:
-            return index.levels[0] if 'date' in self.data.index.names else list(
-                set(self.datetime.date)
+            return index.levels[0] if 'date' in self.data.index.names else sorted(
+                list(set(self.datetime.date))
             )
         except:
             return None