## Description:
More typing improvements.
Switch to using `mypy.ini` for flexibility
Add `warn_return_any` check except in `homeassistant.util.yaml` that does typing hacks. Fix some type annotations as resulting from this check and ignore others were fixing is hard.
## Checklist:
- [x] The code change is tested and works locally.
- [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**
## Description:
Make typing checks more strict: add `--strict-optional` flag that forbids implicit None return type. This flag will become default in the next version of mypy (0.600)
Add `homeassistant/util/` to checked dirs.
## Checklist:
- [x] The code change is tested and works locally.
- [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**
* Add storage helper
* Migrate config entries to use the storage helper
* Make sure tests do not do I/O
* Lint
* Add versions to stored data
* Add more instance variables
* Make migrator load config if nothing to migrate
* Address comments
* Add view to support backend translation fetching
* Load backend translations from component json
* Translations for season sensor
* Scripts to merge and unpack Lokalise translations
* Fix copy paste error
* Serve post-lokalise translations to frontend
* Linting
* Auto-deploy translations with Travis
* Commit post-lokalise translation files
* Split logic into more helper functions
* Fall back to English for missing keys
* Move local translation copies to `.translations`
* Linting
* Initial tests
* Remove unnecessary file check
* Convert translation helper to async/await
* Convert translation helper tests to async/await
* Use set subtraction to find missing_components
* load_translation_files use component->file mapping
* Remove duplicated resources fetching
Get to take advantage of the slick Python 3.5 dict merging here.
* Switch to live project ID
Andrey
Paulus Schoutsen
Adam Mills
Frederik Bolding
Erik Eriksson