Do not log image data in any circumstances
Merge pull request #848 from dionyziz/log_no_images

Do not log image data in any circumstances. (part 1)
Initial tests for setup_db
Refactor setup_db.

* Abstract schema at module level.
* Remove unused `remove_db`.
* Remove unused `main` suite.
* Use `with` aggressively.
* Import modules, not names; simplify imports.