Reorganize tests literals and move then to their respective apps.

mayan/apps/checkouts/tests/test_models.py

@@ -8,13 +8,13 @@ from django.core.files import File
 from django.test import TestCase, override_settings
 from django.utils.timezone import now
 
-from authentication.tests.literals import (
-    TEST_ADMIN_USERNAME, TEST_ADMIN_EMAIL, TEST_ADMIN_PASSWORD
-)
 from documents.models import DocumentType
 from documents.tests.literals import (
     TEST_DOCUMENT_TYPE, TEST_SMALL_DOCUMENT_PATH
 )
+from user_management.tests.literals import (
+    TEST_ADMIN_USERNAME, TEST_ADMIN_EMAIL, TEST_ADMIN_PASSWORD
+)
 
 from ..exceptions import (
     DocumentAlreadyCheckedOut, DocumentNotCheckedOut,