Head over to our Steam Workshop and subscribe to download the gamemode. Bear in mind that the gamemode is still in it's early stages of alpha.
The server files for the gamemode will probably be added to Downloads in the future. But a lot of the core mechanics are still being worked on, so we're going to wait untill we have something more robust to upload.
Untill then, you are free to witness the development process of it on Steam Workshop. (In-steam link)