update python bindings, pygw, to allow for newer versions of python greater than 3.7

[tsandio]

The current version of python is 3.9. Many still use 3.8. However, error checking in your code will cause it to error out if the version is greater than 3.7.

Thanks

[rfecher]

there is a library (or at least at one point was a library) that we depend on that could only work on python <= 3.7 which is where that came in. I'm not actually the expert on the inner workings of pygw so I just checked in and got that conclusion. When we get a chance we will revisit and see if there's anything more we can do about that now.

[tsandio]

Saw that in the requirements after submitting this issue. I believe that the problem is py4j. Thanks for looking into it