Added python-setuptools to the RHEL and Ubuntu guides
Added python-setuptools to the RHEL and Ubuntu guides

See Issue #134
danforthcenter/plantcv,stiphyMT/plantcv,jshoyer/plantcv,stiphyMT/plantcv,jshoyer/plantcv,danforthcenter/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,AntonSax/plantcv,AntonSax/plantcv