title: Style of Popover from React-Bootstrap is not being applied to my component.
body: <p>I am trying to implement <a href="https://react-bootstrap.github.io/components.html#popovers-overlay-trigger" rel="nofollow">Popover with overlay trigger</a> in React - Bootstrap. </p>
  
  <p><a href="http://i.stack.imgur.com/Avb8u.png" rel="nofollow">It is supposed to look like this</a></p>
  
  <p>I implemented it using this code:</p>
  
  <pre><code>var {Button, Overlay, OverlayTrigger, ButtonToolbar, Popover} = require('react-bootstrap');
  
  ...
  &lt;ButtonToolbar&gt;
  &lt;OverlayTrigger trigger="click" placement="left" overlay={&lt;Popover title="Popover left"&gt;&lt;strong&gt;Holy guacamole!&lt;/strong&gt; Check this info.&lt;/Popover&gt;}&gt;
    &lt;Button bsStyle="default"&gt;Holy guacamole!&lt;/Button&gt;
  &lt;/OverlayTrigger&gt;
  &lt;/ButtonToolbar&gt;
  </code></pre>
  
  <p>I compared them using Inspect-Element. I noticed that none of the <code>.popover</code> styling is there for my implementation when I inspected element. Also, there is a <code>pseudo</code> <code>::after</code> element right after the <code>arrow</code> component in the original (the example in the react bootstrap website). That <code>::after</code> component is also missing in my implementation. I am not sure why the style is messed-up/overwritten. I'm including everything correctly I think, as per this line:</p>
  
  <pre><code>var {Button, Overlay, OverlayTrigger, ButtonToolbar, Popover} = require('react-bootstrap');
  </code></pre>
  
  <p>In the end, I cannot see the little arrow of the Popover in my implementation. Why is the <code>::after</code> disappearing? How can I make the little arrow (triangle css) visible in my implementation?</p>