Write install script that will do the web side of setup

[zkat]

Anyone who looks at the README can clearly see that the process of setting up your own wheelie installation can be pretty damn involved. The problem here is that the only way to get all that data and set everything up is to go to the actual site.

It would be really handy if we had a script that collected cookies as needed and set up your herokuapp with minimal interaction, made sure all slash commands are installed, etc. That way, other communities can spin up their own Wheelie instances easily without being stuck with a big shared instance that might not immediately serve their needs.

[dvidsilva]

I added an app.json, as described here https://devcenter.heroku.com/articles/heroku-button

We can add extra commands with the npm hooks.