Update git submodules

Update git submodules

* Update docs/submodules/apex from branch 'stable/euphrates'
  - Merge "Fixes Tacker auth and fernet keys dir" into stable/euphrates
  - Fixes Tacker auth and fernet keys dir

    Tacker authtoken was missing password which is now added in the tht
    patch.  Tacker also needs 'etc/tacker/vim/fernet_keys' in order to be
    able to create VIMs.  The real fix to this missing directory is to the
    rpm itself:

    https://review.rdoproject.org/r/#/c/9725/

    However in this patch we ensure it is created in Ansible because
    RDO images are frozen in for now in Apex so we would not pick up new
    RDO packages.

    apex-tripleo-heat-templates: I2b347cbc4595e6651b0d4be032cb862fde72e15f

    Change-Id: I76959cbfd581b9fec69749ccbcbcb39dc959a883
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit 0c3445f1201cee43f0a167e4c877d95e2c650b50)