title: BootstrapTable2 pagination number of items per page drop down not displaying
body: <p>I'm using <a href="https://react-bootstrap-table.github.io/react-bootstrap-table2/docs/getting-started.html" rel="nofollow noreferrer">BootstrapTable2</a> with Bootstrap4. Everything works except that when I click on the number of items per page, the drop down to select the number of items doesn't display.</p>
  
  <p>Here is my code (it is based off of this <a href="https://react-bootstrap-table.github.io/react-bootstrap-table2/storybook/index.html?selectedKind=Pagination&amp;selectedStory=Basic%20Pagination%20Table&amp;full=0&amp;addons=1&amp;stories=1&amp;panelRight=0&amp;addonPanel=storybook%2Factions%2Factions-panel" rel="nofollow noreferrer">example</a>:
  <div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>import React, {Component} from 'react';
  import BootstrapTable from 'react-bootstrap-table-next';
  import paginationFactory from 'react-bootstrap-table2-paginator';
  
  render(){
  
          const columns =  [
                        {
                            text: "Item",
                            dataField: 'Title',
                            sort: true
                        },
                        {
                            text: "Quantity",
                            dataField: 'Quantity',
                            sort: true
                        },
                        {
                            text: "Needed By",
                            dataField: 'DateNeeded',
                            sort: true
                        },
                        {
                            text: "Requested By",
                            dataField: 'RequesterUsername',
                            sort: true
                        }
                    ]
          return(
              &lt;div&gt;
                  &lt;script src="webjars/popper.js/1.14.7/umd/popper.min.js"&gt;&lt;/script&gt;
  
                  &lt;script src="https://code.jquery.com/jquery-2.2.4.min.js"&gt;&lt;/script&gt;
                  &lt;script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"&gt;&lt;/script&gt;
  
                  {this.state.data != null &amp;&amp; &lt;BootstrapTable keyField='id' bootstrap4 data={ this.state.data } columns={ columns } pagination={ paginationFactory() } /&gt;}
              &lt;/div&gt;
              )
  
      }</code></pre>
  </div>
  </div>
  </p>
  
  <p>Here are my current versions:</p>
  
  <pre><code>"bootstrap": "^4.4.1",
  "jquery": "^3.5.0",
  "popper.js": "^1.16.1",
  "react": "^16.13.1",
  "react-bootstrap": "^1.0.1",
  "react-bootstrap-table-next": "^4.0.1",
  "react-bootstrap-table2-paginator": "^2.1.2",
  </code></pre>