The issues you show don't appear to have anything to do with EPEL. The
certbot package simply requires /usr/sbin/restorecon and
/usr/sbin/semanage; yum isn't able to install those because it appears
that there is some problem with the base (Centos) repositories. Please
make sure that you are able to update your system and install
policycoreutils-python and audit-libs-python on their own without
errors. (Of course the issue might already have cleared itself up by
the time you try.) If you are, then you should be able to install
certbot.
- J<