CentOS 8 instructions need some love

[rlegene]

I'm not sure if you need epel-release still, but now libpcap-devel is only available via powertools. I ran these commands to get libpcap-devel on an almost naked CentOS 8:

To install the dependencies under CentOS 8:

yum install -y epel-release
yum config-manager --set-enabled powertools
sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*
yum install -y libpcap-devel