Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "dep updates related to removing openstack-tripleo"
  - dep updates related to removing openstack-tripleo

    - configure-vm requires libvirt-python
    - removing some references to openstack-tripleo
    - updating dep urls to artifacts.opnfv.org

    JIRA: APEX-462

    Change-Id: I5ed7f7ad2f2c016fcbc1157b29c2c0e4c5d9b4a7
    Signed-off-by: Dan Radez <dradez@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index dd23df3..5bfa41f 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit dd23df3e1ecdf96fa3313114a91a7130566c3a3a
+Subproject commit 5bfa41f042beab7575c94979ac881ce9e721be03