Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Just some job that lightly monitors slaves"
  - Just some job that lightly monitors slaves

    I would like to remove slaves that are offline
    eg: after one month.

    This script doesn't remove anthing, or email anyone, but you can look at
    its output if you are interested.

    Counts how long slaves have been online or offline
    not sure why jenkins doesn't come with this functionality.

    I just threw the script on the master node into
    /opt/jenkins-ci/slavemonitor

    Script writes data to be read the next day, and I don't want to worry about the
    workspace getting wiped.

    you can look at the scipt here:
    https://gist.github.com/Aricg/d770f7d0a4e88d149ddb6715dc4ad0ba
    But I don't recommend it.

    Example of what output looks like:
    JUST WENT OFFLINE arm-build3
    JUST WENT OFFLINE arm-pod5
    JUST WENT OFFLINE ericsson-build3
    JUST WENT OFFLINE ericsson-virtual5
    OFFLINE cengn-pod1 FOR 7 ITERATIONS
    OFFLINE cisco-virtual1 FOR 7 ITERATIONS
    OFFLINE ericsson-virtual8 FOR 7 ITERATIONS
    OFFLINE ericsson-virtual9 FOR 7 ITERATIONS
    OFFLINE intel-pod3 FOR 7 ITERATIONS
    OFFLINE intel-pod6 FOR 7 ITERATIONS
    OFFLINE intel-pod8 FOR 7 ITERATIONS
    OFFLINE intel-virtual1 FOR 7 ITERATIONS
    ONLINE lf-build1 for 6 iterations
    ONLINE lf-build2 for 6 iterations
    ONLINE lf-pod1 for 6 iterations
    ONLINE lf-pod2 for 6 iterations
    ONLINE lf-virtual1 for 6 iterations
    ONLINE lf-virtual2 for 6 iterations
    ONLINE lf-virtual3 for 6 iterations
    ONLINE zte-pod1 for 6 iterations
    ONLINE zte-pod2 for 6 iterations
    ONLINE zte-pod3 for 6 iterations
    ONLINE zte-pod4 for 6 iterations
    ONLINE zte-virtual1 for 6 iterations
    ONLINE zte-virtual2 for 6 iterations
    ONLINE zte-virtual3 for 6 iterations
    ONLINE zte-virtual4 for 6 iterations
    removing online status from arm-build3. slave was online for 1
    iterations
    removing online status from arm-pod5. slave was online for 1 iterations
    removing online status from ericsson-build3. slave was online for 1
    iterations
    removing online status from ericsson-virtual5. slave was online for 1
    iterations

    Change-Id: I652ef5460cb1ce45ff4e87828eb779da7febe8b4
    Signed-off-by: agardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index a020297..f8d75e8 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit a0202977d0c785f67def4ad1c43bb321a6220c68
+Subproject commit f8d75e884b093a2b920ca18d06a02fd1c612ab16