Upgrade to a newer base Docker image

[jsf9k]

💡 Summary

Upgrade to a newer base Docker image. We currently start from a Debian Stretch + Python 3.6 image, and it would be good to use a newer version of Debian as well as a newer version of Python.

Motivation and context

I created this issue because the base image we are using does not support all the hardware platforms listed here.

Implementation notes

This is not a completely trivial change, since some Debian packages that we use have changed names since Stretch.

Acceptance criteria

• [ ] This Docker image uses a newer base image
• [ ] This Docker image continues to function as expected

[jsf9k]

Long resolved by several PRs, most recently #112.