* Updated per review feedback.
* Fixed line length
* Review comments and lint error
* Fixed mypy typeing error
* Moved migration logic to setup
* Use new migration error state
* Fix bug and ignore mypy type error
* Removed SmartThings example and added unit tests.
* Fixed test comments.
* Add test that tests unloading on remove
* Add more test things
* Untangle entity remove code from entity platform
* Don't add default implementation of async_will_remove
* Keep entity weakref alive
* Refactoring data_entry_flow and config_entry_flow
Move SOURCE_* to config_entries
Change data_entry_flow.FlowManager.async_init() source param default
to None
Change this first step_id as source or init if source is None
_BaseFlowManagerView pass in SOURCE_USER as default source
* First step of data entry flow decided by _async_create_flow() now
* Lint
* Change helpers.config_entry_flow.DiscoveryFlowHandler default step
* Change FlowManager.async_init source param to context dict param
* 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
