btn-group-vertical gaps with toggle buttons

Created by: bpierson

btn-group-vertical leaves gaps when used with label-style toggle buttons. On the left is standard vertical group, followed by checkbox and radio versions:

<div class="btn-group-vertical" data-toggle="buttons" role="group">
    <label class="btn-secondary btn">
        <input type="checkbox" /> One
    </label>
    <label class="btn-secondary btn">
        <input type="checkbox" /> Two
    </label>
    <label class="btn-secondary btn">
        <input type="checkbox" /> Three
    </label>
</div>