Added NLog, Added UserService, Added database and seed seed

Birdmap.BLL/Interfaces/IUserService.cs

@@ -0,0 +1,15 @@
+using Birdmap.DAL.Entities;
+using System.Threading.Tasks;
+
+namespace Birdmap.BLL.Interfaces
+{
+    public interface IUserService
+    {
+        Task<User> GetUserAsync(int userId);
+        Task<User> GetUserAsync(string username);
+        Task<User> CreateUserAsync(User user);
+        Task UpdateUserAsync(User user);
+        Task DeleteUserAsync(int userId);
+        Task DeleteUserAsync(string username);
+    }
+}