Removed Unnessecary Imports from: SprintsController

ScrumTaskboard/Controllers/SprintsController.cs

@@ -1,8 +1,6 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;