$user = User::find($id);
        $user->level = 'siswa';
        $user->name = $request->nama_siswa;
        $user->email = $request->email;
        $user->password = bcrypt('rahasia');
        $user->save();
        $request->request->add(['user_id' => $user->id]);
        $siswa = Siswa::create($request->all());
        return redirect('/siswa');