Use https everywhere we can.

[JoelMarcey]

See if this can satisify the Netlify mixed-content warnings

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[brianjo]

I checked the links and the following don't support https:

https://fast.ai (http://fast.ai redirects to https://www.fast.ai/ so change to that URL)
https://deeplearning.net/data/mnist/
https://docs.python-requests.org/en/master/
https://deeplearning.net/data/mnist/
https://proceedings.mlr.press/v9/glorot10a/glorot10a.pdf
https://tflearn.org/
https://localhost:5533/Yourname to get JSON
https://mvapich.cse.ohio-state.edu/
https://man7.org/linux/man-pages/man2/fcntl.2.html
https://minds.jacobs-university.de/sites/default/files/uploads/papers/ESNTutorialRev.pdf

[JoelMarcey]

I think we are still good here with the mixed content tests. Should we go ahead and merge this?