Improve developer workflow with pre-commit

[btjanaka]

Description

Pre-commit is a highly popular framework for installing pre-commit hooks into git projects. This PR adds pre-commit to improve quality-of-life for developers — with pre-commit, developers can easily enforce our style when contributing to pyribs. Adding pre-commit also necessitated fixing files which threw formatting and linting errors.

TODO

• [x] Add pre-commit to CI
• [x] Run YAPF on files and make changes
• [x] Run prettier on Markdown/YAML files and make changes
• [x] Update pylint config — previously, we threw many warnings when running the latest pylint because our pylint config included features only intended for Python 2 compatibility
  • [x] Allow __init__ methods to not have docstrings
• [x] Install pytest in the CI so the tests can import it during the pylint check

Questions

Status

• [x] I have read the guidelines in CONTRIBUTING.md
• [x] I have formatted my code using yapf
• [x] I have tested my code by running pytest
• [x] I have linted my code with pylint
• [x] I have added a one-line description of my change to the changelog in HISTORY.md
• [x] This PR is ready to go