redirect legacy event urls – closes 1020418

This will overwrite redirect.route, so every page will go to the first event id set. STR:

GET http://localhost:7777/events/123 -> https://events.webmaker.org/#!/events/123
GET http://localhost:7777/events/456 -> https://events.webmaker.org/#!/events/123

I wish there was a better way of templating URLs built into Express. Maybe time to pull in a 3rd party module? https://www.npmjs.org/package/url-template might be a neat way of doing it, since you could put the template in the "route" key, then call `expand(req.params)` on it