[settings][settings] Update middleware list

The latest version has a new default set of middleware so update
the list to match it and to keep the current functionality as well
as improve security.

beat/web/settings/settings.py

@@ -313,10 +313,13 @@ TEMPLATES = [
 ]
 
 MIDDLEWARE_CLASSES = (
+    'django.middleware.security.SecurityMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
     'beat.web.navigation.middleware.AgreementMiddleware',
 )