Remove dependency on rdflib-jsonld

[Panaetius]

Closes #93

Requires RDFLib/OWL-RL#46 to be merged and released first, then needs a poetry lock.

Isort reordered some imports in pyshacl/validate.py, I can undo that but as it is right now it should follow the CONTRIBUTING guidelines of the project.

[ashleysommer]

I don't know why Black changed so many lines in various unrelated files in the commit.
I ran re-black and isort on the whole codebase two months ago when I updated the required version of Black to 21.6b0, so they should all already be in the correct state.

Did you run with the given Black config file? black --config=./pyproject.toml ./pyshacl?

Regarding isort, that has a mind of its own. It seems to reorder imports on random files all the time, and a couple of commits later it will re-order them back..

[Panaetius]

I did

$ pip install black==21.6b0
$ black --verbose --config ./pyproject.toml pyshacl

in the virtual env for the project (same with poetry run black ...).

I believe this is correct behavior, see https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#trailing-commas . Black will split a collection of arguments to separate lines if they and in a trailing comma. I remember there used to be a bug in black where, if you call it, it'd add a trailing comma to these kinds of argument lists, which would then cause it to break them onto separate lines if run again (so running black twice didn't yield the same result as running it once). This has since been fixed, but maybe you ran into that issue?

On a side note, we've had good experiences using pre-commit with this config file: https://github.com/SwissDataScienceCenter/renku-python/blob/master/.pre-commit-config.yaml and mentioning in our CONTRIBUTING.md that a user should do pre-commit install. Then black will complain if a user tries to commit a file that wasn't properly formatted. Just a small quality of life improvement you might be interested in.

Edit:
psf/black#1629 this was the black issue, that was in 20.8b0

As for isort, I think it doesn't sort imports past non-import code, so me removing

if owlrl.json_ld_available:
    import rdflib_jsonld  # noqa: F401

caused it to also pickup the imports below that line and sort them

[ashleysommer]

psf/black#1629 this was the black issue, that was in 20.8b0

Yep, looks like you're right. this is that bug. I had pinned our version of black to 20.6b0 back in June because that was the first version which contained the required-version config param, so we could enforce a specific version of black being used.

I'll update it to v20.8b0 to fix that bug.

[ashleysommer]

@Panaetius
PySHACL v0.16.2 is released, with the ImportError bug fixed, and the required version of Black bumped to 21.8b0 to fix the black bug. Reblacked all source files, which brought in the same formatting changes as seen in this PR.

This PR should now be able to be rebased against current Master to make the changeset smaller.

[ashleysommer]

Please rebase or merge against current master

[Panaetius]

I've rebased on current master.