Add deploy-to-tsuru script, README tweaks

This adds a shell script called `deploy-to-tsuru`, that uh, deploys to tsuru.

And then I reference it in `README.md` and made a few other tweaks.

Here's what the output of `deploy-to-tsuru` looks like: https://gist.github.com/msabramo/164f1bdbbd3c56d59df6
I actually originally had a `git push` originally and then I saw `app-deploy`. Do you think `git push` is better?