Add signalr

src/backend/server/Todo/Todo.Api/Hubs/TodoHub.cs

@@ -0,0 +1,13 @@
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.SignalR;
+
+namespace Todo.Api.Hubs
+{
+    public class TodoHub : Hub
+    {
+        public async Task GetInboxTodos()
+        {
+            await Clients.Caller.SendAsync("InboxTodos", "some data");
+        }
+    }
+}