Revert "Adding comment about variable scope and fixing typo"

This reverts commit 2ea96b274bccd76f461e05c475078d5e417ae60d.
Revert "Making InventoryUnit#increase and #decrease use pessmistic lock on variant.count_on_hand update"

This reverts commit e4f60313a285ef0196e5822ffa0c8b91388df0e0.
Entirely bypassing locking for InventoryUnit.increase and making the inventory adjustment an atomic SQL statement
Merge pull request #15 from BuckBuchanan/feature/non-locking-atomic-update-on-inventory-update

Feature/non locking atomic update on inventory update