For all of these routes that call `getUser` you can do a handy little trick here like we do in Popcorn Maker using something called `Express.param`.

See:
https://github.com/mozilla/popcorn.webmaker.org/blob/master/server.js#L134-L135
https://github.com/mozilla/popcorn.webmaker.org/blob/master/server.js#L174-L175
https://github.com/mozilla/popcorn.webmaker.org/blob/master/lib/middleware.js#L16-L50
https://github.com/mozilla/popcorn.webmaker.org/blob/master/routes/api/find.js (uses the project places on `res.locals`)