* Update 4-connection-checking.md
As discussed in https://airbytehq-team.slack.com/archives/C02UQ9MJ4GG/p1655312684160609 - this example is misleading, as it does not actually connect to any API to validate connectivity.
* Update 4-connection-checking.md
Added a link to OneSignal check_connection, and move the "Note" to below the example
* allow importing IncrementalMixin from airbyte_cdk.sources.streams
* format file
* update docs with hint on where to import IncrementalMixin from
* bump cdk version to 0.1.54
* update changelog
* only build python 3.9
* update changelog with python dep bump
* Dockerfile to 3.9
* Python version
* More python updates
* 3.9 on GitHub actions and lint updates
* Test out 3.9.11 on GitHub actions
* install python with an action
* formatting: newline
* Also has python code
* only check first level for changed modules
Previous example (source-google-search-console/credentials)
* Test failure: there is no logger.trace
* add support for streams with state attribute
* fix pre-commit and format
* update state attribute docs and logic
* added IncrementalMixin
Co-authored-by: Eugene Kulak <kulak.eugene@gmail.com>
* Fix broken links found by Ahrefs
* Fix another handbook link
* Fix links in meltano
Co-authored-by: Abhi Vaidyanatha <abhivaidyanatha@Abhis-MacBook-Pro.local>
