FTS-1325: report reason for Unauthorized exception

src/fts3/rest/client/exceptions.py

@@ -28,8 +28,14 @@ class BadEndpoint(FTS3ClientException):
 
 
 class Unauthorized(FTS3ClientException):
+    def __init__(self, reason):
+        self.reason = reason
+
     def __str__(self):
-        return "Unauthorized"
+        if self.reason:
+            return "Unauthorized: %s" % self.reason
+        else:
+            return "Unauthorized"
 
 
 class ClientError(FTS3ClientException):

src/fts3/rest/client/request.py

@@ -65,7 +65,10 @@ class Request(object):
             else:
                 raise ClientError('Bad request')
         elif 401 <= code <= 403:
-            raise Unauthorized()
+            if message: 
+                raise Unauthorized(message)
+            else:
+                raise Unauthorized()
         elif code == 404:
             raise NotFound(url, message)
         elif code == 419: