Update git submodules

* Update docs/submodules/apex from branch 'stable/euphrates'
  - Merge "Minor fixes to clean" into stable/euphrates
  - Minor fixes to clean

    Also adds hidden files (like IDE configs) to gitignore

    Change-Id: Ief595c41c5b4f0fe058f7b774f7a2aefdab733a4
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit 024eb9f773d716e041f064c669690e0e2a727877)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 72759c5..3b0786b 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 72759c59fb710360cd55e27c6f803d2af2c149d3
+Subproject commit 3b0786b9181b944cbcc126ceb85c063924c8744c