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
BTW, I didn't quite finish but I had the idea of making this script general so it could work with other apps besides tsuru-dashboard. 

Idea was user could pass git remote or URL on command-line and it could be automatically deployed to tsuru. This makes it super easy to run existing 12 factor apps on the tsuru infrastructure.