How to remove a list item border in bootstrap list group?

In Bootstrap 4.0 you can simply set each individually or all using the border-* class.

<ul class="list-group">
    <li class="list-group-item border-0">One</li>
    <li class="list-group-item border-top-0">Two</li>
    <li class="list-group-item border-right-0">Three</li>
    <li class="list-group-item border-bottom-0">Four</li>
    <li class="list-group-item border-left-0">Five</li>
<ul />

Bootstrap 4.0 Borders Documententation