FIX: Sudo Requires a TTY on RHEL and SLC

This fixes an issue introduced with the previous Pull Request. Turns out, that RHEL (and therefore SLC) enable the *requiretty* setting of `sudo` by default. Since the cloud testing setup scripts are run without a tty attached they fail on those platforms.

Now the first thing the `remote_setup.sh` does is checking for 'root' permissions and disabling the *requiretty* setting. If it does not run as 'root', it could neither disable the setting nor use `sudo` and would therefore be screwed.