Remove unused code

Remove unused code according to scrutinizer-ci
These should probably not be removed, rather just moved. Look at the comment at https://github.com/SpriteLink/NIPAP/blob/master/pynipap/pynipap.py#L317

This is rendered in the docs (by Sphinx): http://nipap.readthedocs.org/en/v0.25.0/pynipap/#pynipap.VRF.rt

Right now, there is no docs generated for command.py, but if we ever do, it would be nice if we got some comments to these variables.