Change the directory to store docker images

Ubuntu 20.04 image asks to set timezone interactively

A great example where DEBIAN_FRONTEND=noninteractive does its job.

W: GPG error:  InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A4B469963BF863CC
E: The repository '  InRelease' is not signed.

This often happens when I use cudagl base image... NVIDIA recognizes this problem:

You can just add these lines (for Ubuntu18.04)

RUN apt-key del 7fa2af80
RUN apt-key adv --fetch-keys
RUN apt-key adv --fetch-keys