Create py.typed

[Kircheneer]

PEP561 compliancy to enable type checking when Nornir is imported (https://www.python.org/dev/peps/pep-0561/).

This solves an issue where mypy raises "found module but no type hints or library stubs" errors when Nornir is imported to a type-checked module.

[ktbyers]

Did you check/verify that this file will be included with Nornir when uploaded to pypi (given Nornir is using Poetry)?

[Kircheneer]

Did you check/verify that this file will be included with Nornir when uploaded to pypi (given Nornir is using Poetry)?

According to the docs the include/exclude directives are seeded from the .gitignore file - which does not include/exclude the py.typed file. If I download the .tar.gz from Pypi however it does not include everything thats not excluded from the .gitignore. How is a release conducted generally?

[ktbyers]

I think I would test it this way...:

1. Do poetry build and generate a wheel file in the dist directory.
2. Use pip to install that wheel file
3. Verify the py.typed file is included in the directory installed via pip.

I think that would probably be sufficient for verification.

[Kircheneer]

I did the following (using Windows 10 with Git Bash):

$ poetry build
$ cd /other/directory
$ python -m venv venv
$ source venv/Scripts/activate
$ pip install /nornir/dir/dist/nornir-3.0.0-py3-none-any.whl
$ ls venv/Lib/site-packages/nornir
__init__.py  __pycache__/  core/  init_nornir.py  plugins/  py.typed

It looks like the file is indeed included by default.

[ktbyers]

LGTM