add __main__.py back as wrapper

src/pycalver/__main__.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+# This file is part of the pycalver project
+# https://github.com/mbarkhau/pycalver
+#
+# Copyright (c) 2018-2020 Manuel Barkhau (mbarkhau@gmail.com) - MIT License
+# SPDX-License-Identifier: MIT
+"""
+__main__ module for PyCalVer.
+
+Enables use as module: $ python -m pycalver --version
+"""
+from . import cli
+
+if __name__ == '__main__':
+    cli.cli()

test/test_cli.py

@@ -17,8 +17,8 @@ import pytest
 import pathlib2 as pl
 from click.testing import CliRunner
 
-from pycalver import config
 from pycalver import cli
+from pycalver import config
 from pycalver import v1patterns
 
 # pylint:disable=redefined-outer-name ; pytest fixtures