Bump database_cleaner to 0.9.1
Fix StockLocation spec
Revert "Bump database_cleaner to 0.9.1"

Due to randomly failures with SQLite3's locked DB, I have to revert
this commit until database_cleaner sort this out

This reverts commit a726fa2c437e2408d095f6b2b339a61aba3a1ed3.
adding spec and fixing user_logged_in promo rule

Fixes #2884