Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "Increasing clean.py unittest coverage"
  - Increasing clean.py unittest coverage

    Change-Id: Iae3e80b399d1431382614449488238475b47b103
    Signed-off-by: Dan Radez <dradez@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index cbac195..3e4108b 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit cbac19523534a3ffe767c6e44015302222d88a0a
+Subproject commit 3e4108b91fc109b3ec90183051638a16d6713e6f