Empty develop branch NuGet feed

Hi,

I have set up a continuous integration solution for a monogame project on appveyor, and i would like to use the develop branch nugets instead of downloading and installing all monogame framework at each build.

I use the NuGet feed from the download page : http://teamcity.monogame.net/guestAuth/app/nuget/v1/FeedService.svc/
…but it seems to be empty. Am I using the wrong url ?