test/first (#8)

Introducing first very simple tests for tools.py

Reviewed-on: https://www.kuhl-mann.de/git/git/jkuhl/corrlib/pulls/8

corrlib/cli.py

@@ -1,6 +1,6 @@
 from typing import Optional
 import typer
-from corrlib import __app_name__, __version__
+from corrlib import __app_name__
 from .initialization import create
 from .toml import import_tomls, update_project, reimport_project
 from .find import find_record, list_projects
@@ -8,6 +8,7 @@ from .tools import str2list
 from .main import update_aliases
 from .meas_io import drop_cache as mio_drop_cache
 import os
+from importlib.metadata import version, PackageNotFoundError
 
 
 app = typer.Typer()
@@ -15,7 +16,7 @@ app = typer.Typer()
 
 def _version_callback(value: bool) -> None:
     if value:
-        typer.echo(f"{__app_name__} v{__version__}")
+        print(__app_name__, version(__app_name__))
         raise typer.Exit()