Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 7f7fc5a4668aab812c3b3902abe6fc6d69b36a1e
  - Merge "document output of opnfv edge cloud project for hunter release"
  - document output of opnfv edge cloud project for hunter release

    Change-Id: I4a8df5300fefd5048fde9ac5c6c7addd9ef71b22
    Signed-off-by: qihuiz <zhaoqihui@chinamobile.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 3663d72..7f7fc5a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 3663d726c3821e63d9f5cd4a4736a11680534199
+Subproject commit 7f7fc5a4668aab812c3b3902abe6fc6d69b36a1e