Merge pull request #350 from songfei9315/patch-4

Update auth.py

Author: longbai

qiniu/auth.py

@@ -264,8 +264,10 @@ def token_of_request(
         data += "\n"
 
         if content_type and content_type != "application/octet-stream" and body:
-            # data += body.decode(encoding='UTF-8')
-            data += body
+            if isinstance(body,bytes):
+                data += body.decode(encoding='UTF-8')
+            else:
+                data += body
         return '{0}:{1}'.format(self.__access_key, self.__token(data))
 
     def qiniu_headers(self, headers):