Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Remove cli and api

    cli has been deprecated for a while and restapi is uncovered and
    unverified. This patch will be partially reverted as soon as next
    unit tests cover functest/api.

    It partially updates troubleshooting docs which has to be completed
    in a second change [1].

    [1] https://jira.opnfv.org/browse/FUNCTEST-982

    Change-Id: I08e0bd212fcf5f5c5c220eb2500a6b0a6ff46df7
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>