Session is not created during login using Laravel 5.1

When I login to the system using Laravel 5.1 I logged in but session is not created I don't know what's the problem. I'm using AuthController with a little customization. This is the controller:

 public function __construct()
{
    $this->middleware('guest', ['except' => 'getLogout']);
}

/**
 * Get a validator for an incoming registration request.
 *
 * @param  array  $data
 * @return \Illuminate\Contracts\Validation\Validator
 */
protected function validator(array $data)
{
    return Validator::make($data, [
        'username' => 'required|max:255',
        'email' => 'required|email|max:255|unique:users',
        'password' => 'required|min:3',
        'password_confirmation' => 'required|same:password',
    ]);
}

public function postLogin(Request $request)
{
    $this->validate($request, [
        'username' => 'required|alpha_num|max:255',
        'password' => 'required|between:4,10',
    ]);

    if (\Auth::attempt($request->only(['username', 'password']))) {
        return redirect()->intended('/events');
    }
    return redirect()->back()->withInput()->with('error', 'Username Or Password is wrong!');
}

And this is the middleware

class UserMiddleware

{ /** * Handle an incoming request. * * @param \Illuminate\Http\Request $request * @param \Closure $next * @return mixed */ public function handle($request, Closure $next) { if ($request->input('role') == 'admin') { return redirect('/dashboard'); } elseif ($request->input('role') == 'faculty') { return redirect('/events'); } elseif ($request->input('role') == 'student') { return redirect('/news'); }

    return $next($request);
}

}

via Chebli Mohamed