Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - bifrost: Use virtual environment for bifrost

    bifrost forces us to use an old Ansible version which means we can't
    take advantage of new features in XCI playbooks. As such, we move the
    entire bifrost step to a virtual environment so we can have a newer
    version of Ansible on the host.

    Change-Id: I94874d600a29247b7826324cc111901995df90dc
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index d36ba74..3f04e1f 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit d36ba74332cd5e7aeac0b061a5903bcc63a18a20
+Subproject commit 3f04e1fd72b14420788af64b14c35a5f74727f82