Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Provide libvirt credentials"
  - Provide libvirt credentials

    JIRA: FUNCTEST-1004

    This patch provides lbivirt credentials which are required by intel
    testcases run only in fuel at os-nosdn-nofeature-noha scenario.

    Change-Id: I18eeb5dd78c09ea88a0ad49428584824547b6a89
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index a4efde0..fa61619 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit a4efde04f2797f31ee861891a89a7ec2973567df
+Subproject commit fa61619e64d56bee97df49bc0a80fa6bc7c5da79