Clean up README.md

* Fix a broken link to robottelo.
* Add instructions for installing prerequisites.
* Wrap all text at 80 characters.
Merge pull request #36 from Ichimonji10/readme

Clean up README.md
Enable Python 3 compatibility

Make the StringIO import conditional. Add parentheses to print statements.
Refactor function "subscribe"

Try to make the function easy to read, and do make the function
pylint-compliant.