Update dockerfile and requirements to pin versions

[LanesGood]

This PR fixes issues raised in #17 and #15. The only difference between this and #16 are:

• the addition of the --platform tag on the nvidia/cuda image
• a new nvidia/cuda image tag
• replacing python-dev with python2-dev
• lack of the powershell script

[LanesGood]

For your review @worldveil. As I'm not part of the repo it looks like I can't tag you.