Specify version for nvidia/cuda as "latest" tag has been deprecated

[linjungz]

Issue #, if available: #15

Description of changes: As "latest" tag has been deprecated, need to specify a version instead of "latest"

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[rmccarth]

This is needed as it breaks the example here: https://aws.amazon.com/blogs/opensource/virtual-gpu-device-plugin-for-inference-workload-in-kubernetes/ I had to make a manual edit to the .yml I was applying from the example here.

[smartbenson1]

the "image: nvidia/cuda:cuda:11.3.0-runtime-ubuntu18.04" should be "image: nvidia/cuda:11.3.0-runtime-ubuntu18.04" instead.

[wongma7]

https://github.com/awslabs/aws-virtual-gpu-device-plugin/pull/22