Add user deletion

Hcs.WebApp/Services/UsersService.cs

@@ -88,5 +88,11 @@ namespace Hcs.WebApp.Services
             }
             await transaction.CommitAsync();
         }
+
+        public async Task<IdentityResult> DeleteUser(string userId)
+        {
+            var user = await userManager.FindByIdAsync(userId);
+            return await userManager.DeleteAsync(user);
+        }
     }
 }