* Adds test file
* Adds success assertion
* Updates tests
* Updates shelf books creation
* Updates assertion to use isbn for Edition model
* Updates query
* trigger workflow test
* Updates validate_html
* Updates comment and test
* Fixes none test
* Adds management command to clear all deleted user data
* Adds success message
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Co-authored-by: Mouse Reeve <mousereeve@riseup.net>
Co-authored-by: Mouse Reeve <mouse.reeve@gmail.com>
Pylint's `bad-classmethod-argument` is disabled for each definition
to avoid rewriting the method bodies just to rename `self` → `cls`.
This can be done gradually, as the setUpTestData methods are modified
along the way.