So it seems to try to log into email@example.com. Which seems like a terrible idea.
Also it uses a lot of apt-get, so I guess you are limited to linux.
Yes, you are limited to Ubuntu. And yes, the script expects to SSH as root to your server.
As to why it expects that: Doing server provisioning as non-root user does nothing but increase provisioning-complexity.
Deploying as root, on the other hand, is just me being lazy. You're free to fork and send me a pull-request which changes that ;)