Features: 1) Automatically create a new Order if no pending Order exists for authenticated users;

Fixes: 1) Handle `Order.DoesNotExist` exception in `current` method of viewsets;

Extra: 1) Minor improvement to user experience by ensuring an Order object is always returned.

core/viewsets.py

@@ -806,7 +806,10 @@ class OrderViewSet(EvibesViewSet):
     def current(self, request):
         if not request.user.is_authenticated:
             raise PermissionDenied(permission_denied_message)
-        order = Order.objects.get(user=request.user, status="PENDING")
+        try:
+            order = Order.objects.get(user=request.user, status="PENDING")
+        except Order.DoesNotExist:
+            order = Order.objects.create(user=request.user)
         return Response(
             status=status.HTTP_200_OK,
             data=OrderDetailSerializer(order).data,