Added support for Django 2.x

Fixes ViktorStiskala#6

Author: ViktorStiskala

setup.py

@@ -7,7 +7,7 @@
 
 setup(
     name='django-shared-session',
-    version='0.3.3',
+    version='0.4.0',
     packages=['shared_session', 'shared_session.templatetags'],
     include_package_data=True,
     license='MPL',

shared_session/templatetags/shared_session.py

@@ -49,12 +49,13 @@ def encrypt_payload(self, data):
         return box.encrypt(message, nonce)
 
     def get_message(self, request, domain):
-        return urlsafe_base64_encode(self.encrypt_payload({
+        enc_payload = self.encrypt_payload({
             'key': request.session.session_key,
             'src': request.META['HTTP_HOST'],
             'dst': domain,
             'ts': timezone.now().isoformat()
-        }))
+        })
+        return urlsafe_base64_encode(enc_payload).decode('ascii')
 
     def build_url(self, domain, message):
         return urljoin(domain, reverse('shared_session:share', kwargs={'message': message}))