Automatic versioning to easily build development versions from Git

[koenvervloesem]

Is your feature request related to a problem? Please describe.

Currently a development version of the Theengs Gateway Python package can't be easily built because setup.py doesn't have a valid version string. You have to temporarily change this to a valid version string, build the package and then don't forget to restore setup.py again.

Describe the solution you'd like

Automatic versioning from Git tags and commits, as implemented by PyScaffold. This means that every commit can be built without having to manually change a version string.

Describe alternatives you've considered

None

Additional context

This would make it easier for users to test new features in development versions, such as in this case: 1technophile/OpenMQTTGateway#1555 (comment)