title: creatable props not working in react-virtualized-select component
body: <p>I am using 'Creatable' props of <a href="https://github.com/bvaughn/react-virtualized-select" rel="nofollow noreferrer">react-virtualized-select</a>. When I write a custom option(e.g. Test code 4), It shows the text '<strong>create option "Test code 4"</strong>. But, When I click on that option, dropdown becomes blank and that option also not added in option list.</p>
  
  <p>Library Link to demo : <a href="https://bvaughn.github.io/react-virtualized-select/" rel="nofollow noreferrer">https://bvaughn.github.io/react-virtualized-select/</a></p>
  
  <p>Library Link to demo <strong>Source-code</strong> : <a href="https://github.com/bvaughn/react-virtualized-select/blob/master/source/VirtualizedSelect/VirtualizedSelect.example.js" rel="nofollow noreferrer">https://github.com/bvaughn/react-virtualized-select/blob/master/source/VirtualizedSelect/VirtualizedSelect.example.js</a></p>
  
  <p>Options: Below list is coming from database.
  <code>
  dataSource = [
     {name: "Test1", label: "Test code 1", type: "text"},
     {name: "Test2", label: "Test code 2", type: "text"},
     {name: "Test3", label: "Test code 3", type: "text"}
  ]
  </code></p>
  
  <p>Component:</p>
  
  <pre><code>import { Creatable } from 'react-select'
  
  handleOptionChange( selectedValue ) {
     this.setState({
       selectedValue: selectedValue
     });
  }
  
  &lt;VirtualizedSelect
     labelKey='label'
     clearable={ clearable }
     disabled={ disabled }
     multi={multi}
     handleOptionChange={this.handleOptionChange}
     options={ dataSource }
     searchable={ searchable }
     selectedValue={ selectedValue }          
     selectComponent={Creatable}
     valueKey='name'
  /&gt;
  </code></pre>
  
  <p>I could not figure out what else I am missing here ?</p>
  
  <p>Thanks in advance.</p>