Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Remove euphrates jobs"
  - Remove euphrates jobs

    Change-Id: I63fdf2826d2077465f264f082dc1a15eafc2b05a
    Signed-off-by: agardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 4ee0e09..e99861f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 4ee0e0934a6181866cdea70a9bb0c05728e31c7f
+Subproject commit e99861f4bf3ddb3c5bf4edd4458ef0a690345f3f