This file should not have made it back in during merge conflict.
Fix an incorrect inverse_of

This breaks things in strange ways...
AdjustmentSource tests moved into a shared example.

has_many and before_destroy declarations moved into concern.

fixes #5731
Fixes to run tests in windows.

http://stackoverflow.com/questions/23022258/tzinfodatasourcenotfound-error-starting-rails-v4-1-0-server-on-windows

http://stackoverflow.com/questions/10154670/system-cannot-find-the-path-specified-when-running-rake-test-app-with-spree

Fixes #5734
Merge pull request #5747 from gmacdougall/fix-bad-inverse

Fix an incorrect inverse_of
Eager load associations in InventoryUnitBuilder

Everything here will be needed inside coordinator, perhaps we could have
some sort of `assert_no_queries` examples on the build to see whether
and when we miss any records

fixes #5690