Remove requirements.txt and TODO

requirements.txt only lists Ansible 1.3, whereas README.textile says Ansible 1.6+ and has a much more comprehensive discussion of whats required.

TODO only lists 'ensure log rotation' – if that's still a problem it should have an issue created, if not the issue queue provides a much more comprehensive list of tasks. This file seems to be superfluous.

I suggest neither of these files are still required.