Remove unused imports

mayan/apps/common/tests.py

@@ -1,11 +1,7 @@
 from __future__ import absolute_import
 
-from json import loads
-import os
-
 from django.conf import settings
 from django.contrib.auth.models import User
-from django.core.files.base import File
 from django.core.urlresolvers import reverse
 from django.test.client import Client
 from django.test import TestCase