[Bug v2] Expandable styling incorrect

[CollinHerber]

Video of what is happening: https://chicksgold.gyazo.com/37f338d9d9fef76712c8c28516713ff4
Version of aurelia-mdc: v8.0.1-au2

Code:

        <mdc-expandable accordion>
            <div slot="caption">Lorem ipsum dolor...</div>
            Lorem ipsum dolor sit amet, ad erat postea ullamcorper nec, veri veniam quo et. Diam phaedrum ei mea, quaeque
            voluptaria efficiantur duo no. Eu adhuc veritus civibus nec, sumo invidunt mel id, in vim dictas detraxit. Per
            an legere iriure blandit. Veri iisque accusamus an pri.
        </mdc-expandable>
        <mdc-expandable accordion>
            <div slot="caption">Lorem ipsum dolor...</div>
            Lorem ipsum dolor sit amet, ad erat postea ullamcorper nec, veri veniam quo et. Diam phaedrum ei mea, quaeque
            voluptaria efficiantur duo no. Eu adhuc veritus civibus nec, sumo invidunt mel id, in vim dictas detraxit. Per
            an legere iriure blandit. Veri iisque accusamus an pri.
        </mdc-expandable>

[MaximBalaganskiy]

The correct usage in au2 is

<mdc-expandable>
  <div au-slot="caption">Lorem ipsum dolor...</div>
  <template au-slot>
    Lorem ipsum dolor sit amet, ad erat postea ullamcorper nec, veri veniam quo et. Diam phaedrum ei mea, quaeque
    voluptaria efficiantur duo no. Eu adhuc veritus civibus nec, sumo invidunt mel id, in vim dictas detraxit. Per
    an legere iriure blandit. Veri iisque accusamus an pri.
  </template>
</mdc-expandable>