html点击复制兼容clipboard

（参考自 https://clipboardjs.com/）

<input id="foo" value="13456">
<button class="btn" data-clipboard-target="#foo">
    <img src="assets/clippy.svg" alt="Copy to clipboard">
</button>

<script src="clipboard.min.js"></script>
<script>
var clipboard = new ClipboardJS('.btn');

clipboard.on('success', function(e) {
    console.info('Action:', e.action);
    console.info('Text:', e.text);
    console.info('Trigger:', e.trigger);

    e.clearSelection();
});

clipboard.on('error', function(e) {
    console.error('Action:', e.action);
    console.error('Trigger:', e.trigger);
});
</script>