Detect erbb run as root and abort

[ohmtech-rdi]

It can be frustrating for a user to have an error when running erbb, and it is not uncommon for users to use the sudo method in hope it would "force" the operation.

This is something from which the package manager brew has been suffering from for a long time, so it might be quite common.

Detect which user is used when running erbb and abort the operation if it finds that it is run with the root user.