* Moving away from using the root logger everywhere * self.logger -> logger
config[]
config.get()
* Typo fix in CONTRIBUTING.md * Alter references to config.get('FOO') to use preferred config['FOO'] * Set missing configuration constants in superset/config.py * Misc. CI fixes * Add type annotation for FEATURE_FLATGS
* [ci] Deprecate flake8 * Addressing @villebro's comments
* Add LogConfigurator, and add logging for CSV export * tweak for PR feedback * fix linter issue
