gnome-system-tools was showing a warning about Hamara Sugam being an
unsupported platform. g-s-t checks for the presence for debian_version
file in /etc to pass a distro for Debian or Debian-based. Since this
file was not present in Hamara Sugam, checks were failing and the
warning showed up.

Add an empty debian_version file in /etc to avoid any warnings.
Side-effects: None known so far
Tested: OK
Closes re-opened bugzilla entry: https://bugs.hamaralinux.org/show_bug.cgi?id=413

script.
This edits the sources.list in a cleaner way

package as it was causing the builds to fail due to
interactive prompts.

- This would resolve bug #393