Add script to test branches using heroku fork of roobot-test app

[patcon]

There's nothing privileged in roboot-test heroku app. Would be awesome if we could easily spin up a new heroku env, which would also copy all the important envvars from roobot-test.

We could steal the code from here:
https://github.com/heroku/heroku/blob/master/lib/heroku/command/fork.rb

patcon: roobot deploy gittip/roobot@a-feature-branch
roobot: Your feature branch is available here: https://roobot--a-feature-branch.herokuapp.com

[patcon]

Need @whit537's guidance spinning up a heroku instance with fake_data as I would locally. We need one good environment to fork repetitively and deploy commits to via the API.

Is this (the new instance with fake data) something that should be clear to do? It's not obvious to me how to do this easily when non-local.

EDIT: Hm. Rediscovered this chain of issues: gratipay/gratipay.com#1133
So I take it that pushing a fresh site to heroku is non-trivial?