- version update to 0.4.2
* Add logic to populate the ``default`` and ``develop`` package
sections from the ``Pipfile`` to ``with_meta_from``.
* Change validation schema for Requires object to allow for both
``python_version`` and ``python_full_version``.
* Exclude ``pipenv`` section from ``Pipfile`` hash generation as
this was a regression caused by named package categories.
* Add support for named catergories.
* Bug fix.
* Drop Python2 support.