[BUG] "Supported types" documentation is not up to date

[matt035343]

Description

The "Supported types" documentation is not up to date. It states that Python 3.6 is supported and maybe the list of supported types needs to extended. I do not remember if we added any newly supported types.

Code snippet that reproduces the issue

irrelevant

Describe the results you expected

That the documentation is up to date

Python version you are using

irrelevant

Environment description

irrelevant

[george-zubrienko]

I think there are several things we should definitely do:

• Remove 3.6 where it is still mentioned
• Remove 3.7 from unit test matrix, but allow installation on 3.7
• Note that 3.7 has reached EOL and we are no longer providing patches for 3.7
• Update README accordingly