FIX coverage

This was an attempt to fix coverage (back to what it was), confusingly moving around the pep8radius.py file seems to have broken coverage, in the sense that where I test with `check_output`:

    python pep8radius.py --version

Is no longer counted against coverage. This doesn't fix that but does fix a different coverage bug which was that it was testing against the installed pep8radius file (so changes required re-installing to test against).