Khurshid has done a great job of building a meta-package/ppa for us to test unity 7 desktop.
If you are using default ubuntu (18.04) or ubuntu-minimal (mini.iso), you can get whole unity desktop by typing following in terminal:
sudo add-apt-repository ppa:unity7maintainers/unity7-desktop
sudo apt-get update
sudo apt-get install ubuntu-unity-desktop
When prompted choose lightdm as default display manger. Then reboot and login to unity and check everything works as it used to be. If you think a certain package is missing or needs to be updated, file a bug in https://bugs.launchpad.net/ubuntu-unity-meta/+filebug
Our original goal is to move it to universe so that users do not have to add a ppa.