handleItemUpdate = (event, index) => {
 const target = event.target;
 const value = target.value;
 const name = target.name;
 this.setState({
   items: this.state.items.map((item, itemIndex) => {
     if (itemIndex === index) {
       return {
         ...item,
         [name]: value
       }
     }
     return item;
   })
 });
};