## Description:
More fixes flagged by pylint 2 that don't hurt to have before the actual pylint 2 upgrade (which I'll submit soon).
## Checklist:
- [ ] The code change is tested and works locally.
- [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**
* Lazy loading of service descriptions
* Fix tests
* Load YAML in executor
* Return a copy of available services to allow mutations
* Remove lint
* Add zha/services.yaml
* Only cache descriptions for known services
* Remove lint
* Remove description loading during service registration
* Remove description parameter from async_register
* Test async_get_all_descriptions
* Remove lint
* Fix typos from multi-edit
* Remove unused arguments
* Remove unused import os
* Remove unused import os, part 2
* Remove unneeded coroutine decorator
* Only use executor for loading files
* Cleanups suggested in review
* Increase test coverage
* Fix races in existing tests
* Add mysensors notify platform
* Make add_devices optional in platform callback function.
* Use new argument structure for all existing mysensors platforms.
* Add notify platform.
* Update mysensors gateway.
* Refactor notify setup
* Enable discovery of notify platforms.
* Update and add tests for notify component and some platforms.
* Continue setup of notify platforms if a platform fails setup.
* Remove notify tests that check platform config. These tests are not
needed when config validation is used.
* Add config validation to APNS notify platform.
* Use discovery to set up mysensors notify platform.
* Add discovery_info to get_service and update tests
* Add discovery_info as keyword argument to the get_service function
signature and update all notify platforms.
* Update existing notify tests to check config validation using test
helper.
* Add removed tests back in that checked config in apns, command_line
and file platforms, but use config validation test helper to verify
config.
* Add a test for notify file to increase coverage.
* Fix some PEP issues.
* Fix comments and use more constants
* Move apns notify service under notify domain
* added push notification implementation
* some lint changes
* added docs
* added push notification implementation
* some lint changes
* added docs
* Fixed comment formatting issues
* Added requirments
* Update requirements_all.txt
* Update apns.py
* re-generated requirments_all.txt
* Added link to online docs
* added push notification implementation
* some lint changes
* added docs
* added push notification implementation
* some lint changes
* added docs
* Fixed comment formatting issues
* Added requirments
* Update requirements_all.txt
* Update apns.py
* re-generated requirments_all.txt
* Added link to online docs
* changed to use http/2 library for push notifications
* fixed lint issue
* fixed test that fails on CI
* another go at fixing test that fails on CI
* another go at fixing test that fails on CI
* another go at fixing test that fails on CI
* added missing docstring
* moved service description to main services.yaml file
* renamed apns service
