Fix deprecation warnings for Django 1.11 and Django 2.0.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/ocr/tests/test_api.py

@@ -3,7 +3,7 @@ from __future__ import unicode_literals
 import json
 
 from django.contrib.auth import get_user_model
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from rest_framework import status