Stop using outdated manifest stanza; use random-route instead

[mogul]

No description provided.

[pmuellr]

Makes sense, going to test this and make sure it works for me locally, then will merge.

[pmuellr]

I've merged this into master, and it's now available in cfenv 1.2.0 on npm.

Testing it, I see that the "random-route" is now stable across pushes, which I'm pretty sure was not true with the older method, which is awesome!

Thanks so much for your contribution!