fixed condition for installing unittests2

setup.py

@@ -56,7 +56,7 b' requirements = ['
 if sys.version_info < (2, 6):
     requirements.append("pysqlite")
 
-if sys.version_info <= (2, 6):
+if sys.version_info < (2, 7):
     requirements.append("unittest2")
 
 if is_windows: