Add a test for cleaning a deleted account

scripts/lint.sh

tests/integration/Gemfile

tests/integration/Gemfile.lock

tests/integration/boot.rb

tests/integration/konnector/index.js

tests/integration/konnector/manifest.konnector

tests/integration/konnector/on_delete.js

tests/integration/lib/account.rb

tests/integration/lib/album.rb

tests/integration/lib/contact.rb

tests/integration/lib/instance.rb

tests/integration/lib/job.rb

tests/integration/lib/model.rb

tests/integration/lib/stack.rb

tests/integration/lib/trigger.rb

tests/integration/tests/accounts_cleaning.rb