Update git submodules

* Update releases from branch 'master'
  to cbbac7af28caff0222e159ee9007c73c4265d2dd
  - Merge "Release ironic-python-agent-builder 7"
  - Release ironic-python-agent-builder 7

    New major release as we dropped support for tinyipa

    Change-Id: If5f3a8243e2637b17a9bff64ebda636e8894d990
    Signed-off-by: Riccardo Pittau <elfosardo@gmail.com>

diff --git a/releases b/releases
index 98b31aabb9d4d984fe8c89eece9eec3ede301d99..cbbac7af28caff0222e159ee9007c73c4265d2dd 160000 (submodule)
--- a/releases
+++ b/releases
@@ -1 +1 @@
-Subproject commit 98b31aabb9d4d984fe8c89eece9eec3ede301d99
+Subproject commit cbbac7af28caff0222e159ee9007c73c4265d2dd