Adding Pre commit hook

[Casyfill]

Waiting for THIS PR to go first.
Looking forward to confirmation/approval to go over the checklist

Adds pre-commit setup for code style auto-check on any commit. Right now (Draft) linked to my fork of codestyle for testing purposes, once PR is merged, will link to the actual codestyle repository.

How to check / test

1. ensure this file exists
2. install pre-commit: pip install pre-commit. we'll have to add pre-commit to dev requirements
3. run pre-commit install ( installis git hook script into ./git/hooks/pre-commit )
4. Done. Now make any change to python file and try committing - it will run catalyst-make-codestyle automatically and stop without commit if it has job to do (or at least if it fails, but for black it halts if black does any reformating at all).

Pros

• auto check eliminates the need to manually check for codestyle, reminding people to do it, etc
• once "deployed", the script is stored in the .git/hooks/pre-commit file, so all developers get it by default, they don't need to read documentation, install codestyle, etc, etc.
• style requirements can evolve from commit to commit, as we refer to specific hash/version(tag) of codestyle in the repo.

Cons

• adding one more package to the developer requirements list

Side Notes

• we can add other checks, for other languages or datasets as well, if we want. One could check for proper docstring formatting, dead reference links, etc.

Before submitting (checklist)

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contribution guide?
• Did you check the code style? catalyst-make-codestyle && catalyst-check-codestyle (pip install -U catalyst-codestyle).
• Did you make sure to update the docs? We use Google format for all the methods and classes.
• Did you check the docs with make check-docs?
• Did you write any new necessary tests?
• Did you check that your code passes the unit tests pytest . ?
• Did you add your new functionality to the docs?
• Did you update the CHANGELOG?
• Did you run colab minimal CI/CD with latest and minimal requirements?

Description

Related Issue

Type of Change

• Examples / docs / tutorials / contributors update
• Bug fix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves an existing feature)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

FAQ

Please review the FAQ before submitting an issue:

• I have read the documentation and FAQ
• I have reviewed the minimal examples section
• I have checked the changelog for main framework updates
• I have read the contribution guide
• I have joined Catalyst slack (#__questions channel) for issue discussion

Pull request has been modified.

Pull request has been modified.

[Casyfill]

Updated hooks to pull codestyle from official repository (current pr in master). Probably a good idea to switch to release tag once it will be released (or shall we release it as a patch now?)

[Scitator]

catalyst-codestyle==21.06rc1 released :)
PS. somehow I messed with the date, sorry; but it's Release Candidate still (we need to fix config usage there), so nevermind

Pull request has been modified.