Describe the bug
It is currently not possible to apply an elevation to a material card since the class for the card is always the last class defined on the element that is rendered to the page. This means that not only do customizations to the card for elevation not work, but any other customizations to a card instance unless they use !important or inline styles.

To Reproduce

<script>
    import Card from '@smui/card';

</script>

<Card class="menu-container mdc-elevation--z14">
</Card>

Expected behavior
The elevation class, as well as any other classes, should be applied after the class in the rendered order