Cleanups, permissions separation into explicit module, absolute import update

apps/lock_manager/managers.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import
+
 import logging
 import datetime
 
@@ -6,7 +8,7 @@ from django.db.utils import IntegrityError
 from django.db import transaction
 from django.db import models
 
-from lock_manager.exceptions import LockError
+from .exceptions import LockError
 
 logger = logging.getLogger(__name__)