Downshift: Support preact out of the box

[kentcdodds]

@zouhir says he'll be working on this a bit :)

[zouhir]

I had a bit of time to work on this.

my solution includes having a /src/compat/comapt-lite.js and /src/compat/prop-type.js to insure Preact's compatibility with proptypes and the React component.

Also, in rollup config, I did alias the react & prop-types to those 2 files in source.

Blocker:
The React rolled up version of this has a bit of an issue (pure react, no alias entry, no change)

• 😁 component loads fine!
• 😁 I can click and see drop down fine!
• 😔 When I choose a country I get the Error attached. I am afraid it's some babel or something else.

Since I've not fiddled much with react libs in details recently, appreciate looking at this error am getting:

I'll share my WIP branch here as well

[kentcdodds]

If you rebase your branch onto master that should now be resolved :+1: