fix test for python 2.5

.travis.yml

@@ -2,7 +2,6 @@
 
 language: python
 python:
-  - "2.4"
   - "2.5"
   - "2.6"
   - "2.7"

tests/client-test.py

 #encoding=utf-8
-from __future__ import unicode_literals
 import unittest
 import sys
 import os