Django 2.0 compatibility: User.is_authenticated is now a property.

Fixes #397

Author: sciyoshi

ddtrace/contrib/django/compat.py

@@ -0,0 +1,9 @@
+import django
+
+
+if django.VERSION >= (2,):
+    def user_is_authenticated(user):
+        return user.is_authenticated
+else:
+    def user_is_authenticated(user):
+        return user.is_authenticated()

ddtrace/contrib/django/middleware.py

@@ -2,6 +2,7 @@
 
 # project
 from .conf import settings
+from .compat import user_is_authenticated
 
 from ...ext import http
 from ...contrib import func_name
@@ -134,7 +135,7 @@ def _set_auth_tags(span, request):
         return span
 
     if hasattr(user, 'is_authenticated'):
-        span.set_tag('django.user.is_authenticated', user.is_authenticated())
+        span.set_tag('django.user.is_authenticated', user_is_authenticated(user))
 
     uid = getattr(user, 'pk', None)
     if uid: