Remove references of .card-deck-wrapper

Created by: Quy

.card-deck-wrapper is not required with flexbox mode.

By default, card decks require two wrapping elements: `.card-deck-wrapper` and a `.card-deck`. We use table styles for the sizing and the gutters on `.card-deck`. The `.card-deck-wrapper` is used to negative margin out the `border-spacing` on the `.card-deck`.