disable new user registration since we'll be using AD later

app/Http/Controllers/Auth/RegisterController.php

@@ -68,4 +68,13 @@ class RegisterController extends Controller
             'password' => bcrypt($data['password']),
         ]);
     }
+    public function showRegistrationForm()
+    {
+        return redirect('login');
+    }
+
+    public function register()
+    {
+      abort(404);
+    }
 }