Add Optix 6.0 support

Applications that use nVidia Optix 6.0 apparently rely on certain runtime dependencies typically deployed with (or built-into) the nvidia proprietary driver. While I'm able to run Optix 5.1 applications within the centos7 cuda containers, I'm encountering runtime exceptions with Optix 6.0 applications inside a similar (lacking Optix 5.1 libraries) container since (speculation) not all of the libraries/files needed by Optix 6.0 apps are being mounted from the host. The same app runs fine on my host system outside of docker.

There is an ongoing discussion over on the nvidia forums, but this appears to require an image update to address, so thought it best to follow it as an issue with the containers rather than a forum post.

To reproduce, try to run applications built for and using Optix 6.0 in the centos7 cuda 10.0 containers.