Make this work in preact.

[2betop]

Without key prop the input element unmounted and remounted after input changed, and the "onblur" handler make the panel dismissed soon.

[coveralls]

Coverage remained the same at 91.994% when pulling a1862d2 on 2betop:patch-1 into bd1fb2c on JedWatson:master.

[JedWatson]

Thanks @2betop!

Let me know if you're interested in adding an example entrypoint that uses preact so we can continue to test it and support preact going forward 👍