title: Use different key for searching instead of value or label in react-select in reactJS
body: <p>I am using react-select as a searchable drop-down in my react app.
  I am referring this link <a href="https://github.com/JedWatson/react-select" rel="noreferrer">https://github.com/JedWatson/react-select</a>.</p>
  
  <p>In the drop-down options structure, it needs <code>label</code> and <code>value</code> keys in the respective object in <code>options</code>.
  My problem is, I dont have any <code>label</code> or <code>value</code> in my <code>options</code> data.
  I am having different keys altogether.
  I want the drop-down to be searched by different key <code>tab</code>.</p>
  
  <ul>
  <li>My React version : 15.6.2 </li>
  <li>react-select version : 1.0.0-rc.10</li>
  </ul>
  
  <p>My code for drop-down:</p>
  
  <pre><code>&lt;Select
     name="selectSubTag"
     id="selectSubTag"
     value={this.state.selectedFilter.subTag}
     options={this.state.jobSubTags}
     onChange={this.setSubTag}
     placeholder="Select Sub Tag"/&gt;
  </code></pre>
  
  <p>Where my <code>options</code> data looks like below:</p>
  
  <pre><code>    this.state.jobSubTags = [
  {tab:"tabName 1",tabValue:1},
  {tab:"tabName 2",tabValue:2},
  {tab:"tabName 3",tabValue:3},
  ]
  </code></pre>
  
  <p>and now I want the data to be searched by 'tab' key in the dropdown.</p>