I am trying to add following dlls using Nuget but I am getting items not found.
https://blogs.msdn.microsoft.com/webdev/2015/09/15/sending-webhooks-with-asp-net-webhooks-preview/
NuGet Package Manager 2.8.60318.667
Use NuGet package manager console from the tools menu and use this command, because this is a pre-release version you cannot get it from the NuGet gui window
Install-Package Microsoft.AspNet.WebHooks.Custom -Pre