Add hashing to the API

See merge request pv080/pv080_crypto!3

While both words are correct cryptographic is used much more. You can
check Google Books Ngram Viewer to see the huge difference.

Yes, parsing YAML and producing a Bash commands out of it might not have
been the brightest of ideas, when it fails on a single white space.
Thanks to whoever thought of that. I'll sleep better now knowing there
is one more thing to keep in mind.

`pyproject.toml` is now _the way_ to handle Python projects if I am not
mistaken. Duplicating dependencies in `requirements.txt` and
`dev-requirements.txt` is a source of issue (as was my own experience
just now).

When you install this package using
```
pip install --editable .
```
The `build` folder is created

I have missed the docstring tests and decided to add normal tests.
Only later I saw that we indeed do have tests for AES, but then I wanted
to add them anyway...