Utility to let you have a single source version in your code base.
This utility targets modern Python projects which have layout generated
by Poetry, with a pyproject.toml file in place of setup.py. With this
layout, the project initially has two places to maintain the version
string: one in pyproject.toml and one in some *.py file (normally
__init__.py). This duplicity often leads to inconsistency when you the
author forget to update both.
single-version was born to solve that headache circumstance. By convention,
it chooses the pyproject.toml file as original source of version string.
