Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Make the vnf images public"
  - Make the vnf images public

    Openims and clearwaterims use the same ubuntu image. If the image
    was createed by the openims without 'public', clearwaterims won't
    create it again but cannot use the image and report 'Not Found'
    error [1].

    Change-Id: Ib691af2992b1de2a13f54bfa46754afba6152fd9
    Signed-off-by: Alex Yang <yangyang1@zte.com.cn>