Guide to install a newer version of Podman on Centos can be found on podmans website https://podman.io/getting-started/installation.html This will get you a newer version than 1.4 which is included in the default yum repository.
CentOS 7 is using an older kernel that does not support all features of podman. One thing is that needs to be removed is mount options with metacopy. You can change this line by removing metacopy=on in
mountopt = "nodev,metacopy=on"
If you do not do this you will get an error then trying to use podman, as the one below.
[email@example.com podman]# podman ps -a Error: error creating libpod runtime: failed to mount overlay for metacopy check: invalid argument