Fix deprecation warnings for Django 1.11 and Django 2.0.

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

mayan/apps/documents/views/document_page_views.py

@@ -5,8 +5,8 @@ import urlparse
 
 from django.conf import settings
 from django.contrib import messages
-from django.core.urlresolvers import reverse
 from django.shortcuts import get_object_or_404
+from django.urls import reverse
 from django.utils.http import urlencode
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic import RedirectView