Update composer.json

Thist code doesn't work for my app:
```php
<?php echo \cebe\gravatar\Gravatar::widget(
                                    [
                                        'email'   => \Yii::$app->user->identity->profile->gravatar_email,
                                        'options' => [
                                            'alt' => \Yii::$app->user->identity->username
                                        ],
                                        'size'    => 128
                                    ]
                                ); ?>
```

and profile ... hm