clan-cli: initialize python project from template

clan-cli: remove unnecessary unit test file

clan-cli: fix shell.nix too stateful

clan-cli: remove conftest.py

clan-cli: fix flake-module.nix

pkgs/clan-cli/tests/test_cli.py

@@ -0,0 +1,16 @@
+import sys
+
+import my_tool
+
+
+def test_no_args(capsys):
+    my_tool.my_cli()
+    captured = capsys.readouterr()
+    assert captured.out.startswith("usage:")
+
+
+def test_version(capsys, monkeypatch):
+    monkeypatch.setattr(sys, "argv", ["", "--version"])
+    my_tool.my_cli()
+    captured = capsys.readouterr()
+    assert captured.out.startswith("Version:")