First five will now clone a given repo

In order to reconcile the paradox of wanting to keep First Five up to
data and allowing users to keep their configurations in a repo of their
own, I've decided to convert to the RVM model of things. The most recent
infect.sh will live in GitHub and you may run it by executing the
following command:

curl https://raw.github.com/AndrewGuenther/firstfive/master/infect.sh |
bash -s <repo url>
Migrating to the remote model

This repository now only holds the infect script which takes either a
git repository or a folder as an argument, clones it, and then performs
the same operations as previous versions.

This way, users can keep their own configuration file repositories
without having to worry about staying up to date with the infect script.