Ask if nvidia-modprobe is installed
Ask if nvidia-modprobe is installed

Improve error message with hint about nvidia-modprobe being installed

Closes: #126
Signed-off-by: Felix Abecassis <55aebb135999a2c3fc3e3a88716154833ef9e5ed@nvidia.com>

NVIDIA/nvidia-docker,mvechava/nvidia-docker,mvechava/nvidia-docker,mvechava/nvidia-docker