Refactor existing tox test to pytest

[s-cu-bot]

Description

[What I changed]
(1) requirements-dev.txt

• Added pytest-xdist
• pytest plugin that supports parallel processing

(2) file_format_test.py

• "setup_test_result_dir_and teardown" is a logic to temporarily create a test directory and then delete it when the test ends.
• "run_command" is a function that helps you execute Linux commands (prints success and result values)
• "test_output_file_format" checks whether files are created normally in excel, csv, json, and yaml format.

(3) initial_tox_test.py

• "setup_test_result_dir_and teardown", "run_command" are the same as file_format_test.py
• “test_release_environment”, "test_test_run_environment" are the same as the existing tox process.
• Only refactoring is performed through pytest (errors can be checked through assert statements, and additional verification is possible)

(4) tox.ini

• Change the entire test code running in the file on a file/function basis.
• Parallel execution of test cases via pytest (-n flag)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation update
• Refactoring, Maintenance
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

[cjho0316]

LGTM

[YongGoose]

깔끔하게 잘 해주신 것 같습니다 :)

많이 배우고 갑니다.

[ena-isme]

많은 참고가 되었습니다:) 수고하셨어요!

[MoonJeWoong]

고생하셨습니다! 크게 고칠만한 부분은 보이지 않는 것 같아서 코멘트 달아주신 부분만 확인해주시면 될 것 같습니다~