Hello, great library!

Just wanted to bring to your attention that mixins/dropdown.js#L123 returns an array that contains a single Nodelist, instead of an array that contains nodes (as you wanted, by using the spread operator).

Either:
return Array.prototype.slice.call( this.$refs.menu.querySelectorAll(ITEM_SELECTOR) )

or

return [].concat.apply( [], this.$refs.menu.querySelectorAll(ITEM_SELECTOR) )

...would give you the items in array format.

Thank you for all the work!