Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[cleanup] Move default storage dir to /var/lib"
  - [cleanup] Move default storage dir to /var/lib

    Since we switched to dockerized Salt master and mounting the full
    contents of the current git repo inside cfg01's /root/fuel dir,
    exposing temporary deploy artifacts should be avoided, i.e. the
    default temporary storage location (configurable via '-S' deploy arg)
    should be moved outside the git repo.

    JIRA: FUEL-383

    Change-Id: I32f7197b018fd853867de42f5618650ac9022dc9
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>