Overview of changes:

 *  Added CentOS support to /etc/system-release parser

 *  Updated Shellfu requiurements to latest&greatest

    There were some changes related to older distros, so let's keep them
    updated to make best use of dist.sh

 *  Fixed URL after moving to pagure.io

 *  Fixed copy/pasting error in README.md

Overview of changes:

 *  Codebase maintenance