title: react-select multiple option
body: <p>I'm trying to set <code>react-select</code> component for simple <code>select</code> with <code>multiple</code> options but i can't get it working even though it's everything set as docs say. When <code>multi</code> is <code>false</code>, <code>Select</code> works as intended with one <code>value</code> at a time, but when i set <code>multi={true}</code> it shows <code>value</code> as <code>undefined</code>.</p>
  
  <p>When i give in <code>handleChange()</code> <code>event.target.value</code> it gives <code>undefined</code> aswell so thats why i've just used <code>event.value</code> to grab obj property. I'm still newbie to React so any tips about <code>state</code> would be appreciated if i'm doing something wrong here -_-</p>
  
  <pre><code>class StatisticsFilter extends Component {
    constructor(props) {
      super(props);
      this.state = {value: ''};
  
      this.handleChange = this.handleChange.bind(this);
    }
    handleChange(event) {
      this.setState(event.value);
    }
  
  const options =
  [
    {
      value: 'foo', label: 'Foo'
    },
    {
      value: 'bar', label: 'Bar'
    },
    {
      value: 'baz', label: 'Baz'
    }
  ];
  
    render() {
      return (
            &lt;Select
                value={this.state.value}
                name="filter__statistics"
                options={options}
                onChange={this.handleChange}
                multi={true}
            /&gt;
      );
    }
  }
  </code></pre>
  
  <p>Using <code>react-select v. 1.0.0rc</code>.</p>