There is a now a beta build available that supports Oculus Rift Runtime 1.3 and HTC Vive / SteamVR (it should therefore work with OpenVR / Razer OSVR too!)

To get this build, right hand click on the game in your Steam library, go to the betas tab and choose "rift_vive_osvr_test" options. This will then patch the game to this beta build