Fix datetime_tz import

tests/test_client.py

@@ -6,7 +6,7 @@ import nilmdb.client
 from nilmdb.utils.printf import *
 from nilmdb.utils import timestamper
 from nilmdb.client import ClientError, ServerError
-from nilmdb.utils import datetime_tz
+import datetime_tz
 
 from nose.plugins.skip import SkipTest
 from nose.tools import *