Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "Increase memory size for virt-customize"
  - Increase memory size for virt-customize

    Some of the bigger commands can exceed the default,
    so increase all instances for consistency. It's
    unlikely build machines won't have 4G of memory
    available.

    Change-Id: Ifa575b6e6faef9ba038900ab0e080da15d5680aa
    JIRA: APEX-520
    Signed-off-by: Michael Chapman <michapma@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 4c81410..f941e23 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 4c8141069f9adf7d315bc53c236d8e7928030def
+Subproject commit f941e233e575821695dc876c9a7a9f6c31e6dd00