strictly match cuda version when installing cudnn

I was naive to think that a cudnn version built for CUDA 10.1 will work with CUDA 10.0 installed in my machine. This mismatch will not produce any explicit error messages when building and training a tensorflow model. However, I notices that the loss does not reduce even after a noticable amount of steps and epochs.

When I replaced my cudnn to a version that was targeted to CUDA 10.0, and reran the training session, the loss does significantly reduce at the beginning.