Update middleware to new style classes

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

mayan/apps/common/middleware/ajax_redirect.py

@@ -2,9 +2,10 @@ from __future__ import unicode_literals
 
 from django.conf import settings
 from django.http import HttpResponseRedirect
+from django.utils.deprecation import MiddlewareMixin
 
 
-class AjaxRedirect(object):
+class AjaxRedirect(MiddlewareMixin):
     def process_request(self, request):
         ajax_referer = request.META.get('HTTP_X_ALT_REFERER')
 

mayan/apps/common/middleware/error_logging.py

@@ -4,11 +4,12 @@ import logging
 
 from django.core.exceptions import PermissionDenied
 from django.http import Http404
+from django.utils.deprecation import MiddlewareMixin
 
 logger = logging.getLogger(__name__)
 
 
-class ErrorLoggingMiddleware(object):
+class ErrorLoggingMiddleware(MiddlewareMixin):
     def process_exception(self, request, exception):
         if not isinstance(exception, (PermissionDenied, Http404)):
             # Don't log non critical exceptions

mayan/apps/common/middleware/timezone.py

@@ -4,9 +4,10 @@ import pytz
 
 from django.conf import settings
 from django.utils import timezone
+from django.utils.deprecation import MiddlewareMixin
 
 
-class TimezoneMiddleware(object):
+class TimezoneMiddleware(MiddlewareMixin):
     def process_request(self, request):
         if hasattr(request, 'session'):
             tzname = request.session.get(settings.TIMEZONE_SESSION_KEY)