v2.4.0.post1

This update to the HELICS PyPI package has the following changes:

• Fixes the pip source distribution package; the previous v2.4.0 release was missing the bundled source code for the Python interface
• Fixes handling of Visual Studio CMake generator to enable a source distribution build to work on msys2
• Switches versioning to versioneer to simplify managing versions and enable unique versions for test builds
• Uploads test builds to test.pypi.org/project/helics all commits to master
• Enables a test build of the pip packages for PRs to master

v2.4.0

Package updates for HELICS 2.4.0 release:

• Added a Python package for to PyPI that can be installed with pip install helics using precompiled binary wheels on a variety of supported platforms