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
Wow. I will create a plugin list in the documentation to list the existing plugins.

Related with this PR, you will create a plugin for the deploy from github?