Update git submodules
* Update docs/submodules/releng from branch 'master'
- Merge "[yardstick] debug dump image ID"
- [yardstick] debug dump image ID
we need to know if we are pulling stale yardstick/stable images
for example, if when branching between releases we can
still be pulling old release yardstick/stable images without
knowing it.
This will dump the IMAGE ID of the images we just pulled which
we can match to Jenkins docker push builds
Change-Id: I875cf2fd07d17c3eebe294e70f2edccd9f48ce11
Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>