Fix CI where tests were breaking for linters and Celery

[vatsalyagoel]

Remove Unused Classes and Test File

• tasks.py has a function update_github_score which updates properties (github_score and fav_language) neither of which exist as model properties. The function is not referenced anywhere in the project either
• test_tasks had a bootstrapped test that is calling a non-existent function

Linting Fixes

• Trim Trailing White-space
• Fix End of Files
• check Yaml
• sort references
• Fix Flake8 tests

[vatsalyagoel]

I don't have merge permissions. Someone from the contributors group will need to merge :)