title: b-form-select VUE bootstrap style/CSS issue
body: <p>I'm new working with VUE, but until the moment i already read and try some suggestions, but the issue continues.</p>
  <p>I'm trying to use this one:
  <a href="https://bootstrap-vue.org/docs/components/form-select" rel="nofollow noreferrer">Form Select - Bootstrap</a> ( like the example )</p>
  <p>When i check my local host page I have:</p>
  <p><a href="https://i.stack.imgur.com/Xav01.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Xav01.png" alt="Wrong style" /></a></p>
  <p>In the code I have:</p>
  <ul>
  <li>Main.js</li>
  </ul>
  <pre><code>import {BootstrapVue, IconsPlugin, FormRatingPlugin, FormSelectPlugin  } from 'bootstrap-vue';
  import 'bootstrap/dist/css/bootstrap.css'
  import 'bootstrap-vue/dist/bootstrap-vue.css'
  
  Vue.use(BootstrapVue)
  Vue.use(IconsPlugin)
  Vue.use(FormRatingPlugin)
  Vue.use(FormSelectPlugin)
  
  Vue.component('b-form-select', BFormSelect)
  
  </code></pre>
  <ul>
  <li>Partner.js</li>
  </ul>
  <pre><code>[template]
  &lt;b-form-select 
      v-model=&quot;selected2&quot; 
      id=&quot;socioPack&quot;  
      name=&quot;socioPack&quot; 
      :options=&quot;options2&quot;&gt;
  &lt;/b-form-select&gt;
  &lt;div class=&quot;mt-3&quot;&gt;Selected: &lt;strong&gt;{{ selected2 }}&lt;/strong&gt;&lt;/div&gt;
  &lt;/div&gt;
  
  
  [data()]
  
  selected2: null,
  options2: [
      { value: null, text: 'Please select some item' },
      { value: 'a', text: 'This is First option' },
      { value: 'b', text: 'Default Selected Option' },
      { value: 'c', text: 'This is another option' },
      { value: 'd', text: 'This one is disabled', disabled: true }
  ]
  
  </code></pre>
  <p>Can someone give me a tip?</p>
  <p>Let me know if more details needed.</p>