Sync Patch and PatchObject fixtures from oslo-incubator

This change allow us to set a replacement function to these fixtures.
Depends on I32a90b4d47174b6adb53b525a4add7002411b29d

Change-Id: I897db568280c026f92f7f6da8c1ea974274fc037
Merge "Sync Patch and PatchObject fixtures from oslo-incubator"