Putting some make-up on the install.sh script"
- This relies on the `/etc/os-release` file which is present on all modern distributions that you are currently supporting. More info on: https://www.freedesktop.org/software/systemd/man/os-release.html
- I've taken the liberty of including a warning message for CentOS 8 / CloudLinux 8
- I've also derived `SERVER_OS` from the proper strings. I suggest you end up using a variable directly from `/etc/os-release` instead, tough, as it's just extra-fluff right now, and it seems you are using it just for statistics purposes
- I have also switched to using `printf >&2` to output the messages to `stderr` instead of `stdout` because they are technically warnings
