title: Not able to set active-class for selected button in Vuetify v-btn-toggle
body: <p>I am using Vuetify <code>v-button-toggle</code> to toggle between three buttons like below. And each button has different active class. But clicking on a button does not set the active respective active class. What I am missing?</p>
  
  <pre><code>&lt;v-btn-toggle
    v-model="justify"
    borderless
    dense
    group
    class="d-flex flex-column "
  &gt;
    &lt;v-btn active-class="dnrSelected" exact&gt;
      &lt;v-icon right class="mr-2"&gt;mdi-close&lt;/v-icon&gt;
      &lt;span&gt;Do Not Recommend&lt;/span&gt;
    &lt;/v-btn&gt;
    &lt;v-btn active-class="rSelected"&gt;
      &lt;v-icon right class="mr-1"&gt;mdi-check&lt;/v-icon&gt;
      &lt;span&gt;Recommend&lt;/span&gt;
    &lt;/v-btn&gt;
    &lt;v-btn active-class="srSelected"&gt;
      &lt;v-icon right class="mr-1"&gt;mdi-check-all&lt;/v-icon&gt;
      &lt;span&gt;Strongly Recommend&lt;/span&gt;
    &lt;/v-btn&gt;
  &lt;/v-btn-toggle&gt;
  </code></pre>
  
  <p>CSS classes</p>
  
  <pre><code>&lt;style scoped&gt;
    .dnrSelected {
      background-color: #e57373;
    }
    .rSelected {
      background-color: #c5e1a5;
    }
    .srSelected {
      background-color: #81c784;
    }
  &lt;/style&gt;
  </code></pre>
  
  <p>Update: As expected class is added to the button on click</p>
  
  <pre><code>&lt;button type="button" class="v-btn srSelected v-btn--active v-btn--contained theme--light v-size--default"&gt;&lt;span class="v-btn__content"&gt;&lt;i aria-hidden="true" class="v-icon notranslate mr-1 v-icon--right mdi mdi-check-all theme--light"&gt;&lt;/i&gt; &lt;span&gt;Strongly Recommend&lt;/span&gt;&lt;/span&gt;&lt;/button&gt;
  </code></pre>
  
  <p>Update: Default Vuetify class below is overriding the custom style</p>
  
  <pre><code>.v-btn-toggle--group &gt; .v-btn.v-btn {
    background-color: transparent !important;
    border-color: transparent;
    margin: 4px;
    min-width: auto;
  }
  </code></pre>
  
  <p>How to override this default style class?</p>