Build releases for python versions 3.8 and 3.9

[ctrl-z-9000-times]

Now that we know python 3.9 works, we should build and release it for 3.8 and 3.9 on all platforms.

[ctrl-z-9000-times]

After this PR is merged I'm going to make a new release, using the github feature.
The release script should upload a new distribution to the pypi test server.
This will make the latest version "v2.1.16"

[dkeeney]

Once this works, what does it take to move from the test server to the production pypi server?

[ctrl-z-9000-times]

@dkeeney

There are two things that need to be done to move to the production server:

1. The URL for pypi in our build scripts needs to be changed (very simple to do),
2. We need an account for the production server, and github needs an API token for it. I don't know who controls what accounts, or how they are managed....

[dkeeney]

I don't know if @breznak or Matt had set up an account. I don't know how to do this but perhaps we could look to see if an account exists and if it does not, then go ahead and create one. I don't think the testing account is tied to the production account but not sure. Sorry I am not much help.

[ctrl-z-9000-times]

That's fine
What's important is that we get the 38 and 39 artifacts built and uploaded to some where that's publicly accessible.
These newer versions of python are clearly starting to show up in the wild...
I'll start a separate issue for moving to the real pypi server?

[ctrl-z-9000-times]

See issue #952

[breznak]

thanks for the py3.9 builds! 👍

I don't know if @breznak or Matt had set up an account.

I think only Matt had that pypi.org account. We can ask someone from Numenta or just create a new user for htm.core