PEP 517 build management

[eccles]

Is your feature request related to a problem? Please describe.
Currently uses setuptools which is now deprecated.

Describe the solution you'd like
Use PEP 517 standard. - best practice.

[eccles]

Preliminary investigation reveals that documentation should be read from here:

https://packaging.python.org/en/latest/tutorials/packaging-projects/

there are other sources of info but they seem unworkable... https://peps.python.org/pep-0517/ does not allow getting the version from the git tag...

[eccles]

So in conclusion PEP 517 is half-cooked and this PR should be deferred until things have improved.

[eccles]

Leave for a later version of python such as 3.9 perhaps

[eccles]

This link https://github.com/dib-lab/screed/pull/83/files is useful example