title: react-table iterating over object array to print values in a column
body: <p>I am using react-table to generate tables(<a href="https://react-table.js.org/#/story/readme" rel="noreferrer">https://react-table.js.org/#/story/readme</a>). I have a state defined as following:</p>
  
  <pre><code>this.state = {
  
      sampleTable:[
          {author: 'Mac', books: [{title:'One', price: 20}, {title:'Two', price: 20}]},
          {author: 'Rick', books: [{title:'Three', price: 20}, {title:'Four', price: 20}]}
      ],
  
      sampleTableColumns:[
          {Header: 'Author', accessor: 'author'},
          {Header: 'Books', accessor: 'books.title'},
      ],
  };
  </code></pre>
  
  <p>And I am trying to make table as following:</p>
  
  <pre><code>&lt;ReactTable
      className="-highlight"
      data={this.state.sampleTable}
      columns={this.state.sampleTableColumns}
      defaultPageSize={10}
  /&gt;
  </code></pre>
  
  <p>However in the books column I see nothing. I am not sure how am I supposed to iterate over books array so that I can print say book titles in books column?</p>