Switch to py38

Directly get 'all' from settings since it's always present

Fix settings handling (#78)

Fix settings handling

Merge pull request #76 from SublimeLinter/simplify-cmd

Remove unused `_inline_setting_bool()`

Make additional settings 'all' and 'coverage' explicit

Simplify `cmd` which can be stated declaratively

Fix status badge code

Update status badge

Merge pull request #75 from SublimeLinter/do-not-use-persist-debug

Fix lint error

Add flake8 config

Add flake8 GitHub action, remove travis

Replace `persist.debug` with `logger.info`