import React from 'react'

class CardList extends React.Component {

	render() {
		return (
			<ul>
				{this.props.cards.map(card => <li>{card.url}</li>)}
			</ul>
		)
	}

}

export default CardList

import React from 'react'
import Card  from './card'

class CardList extends React.Component {

	render() {
		return (
			<ul>
				{this.props.cards.map(card => {
					return <li>
						<Card {...card} />
					</li>
				})}
			</ul>
		)
	}

}

export default CardList

Use Card instead of text inside CardList
Use Card instead of text inside CardList