I have made a breaking change to the apt.kura.io repositories.
Ubuntu is now properly supported, but to do this properly it meant separating Ubuntu and Debian in to totally separate sections to fix the dependency issues.
Anyone currently using apt.kura.io as it is will get 404 errors and will need to reconfigure their APT settings.
sudo sed -i 's/apt.kura.io\//apt.kura.io\/debian\//g' /etc/apt/sources.list.d/apt.kura.io.list
sudo sed -i 's/apt.kura.io\//apt.kura.io\/ubuntu\//g' /etc/apt/sources.list.d/apt.kura.io.list