Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Set swift_operator_role if required

    Apex creates member as default role which conflicts with the default
    swift_operator_role [1]. It detects the default role in lowercase as
    well and write it in rally.conf if required.

    [1] https://build.opnfv.org/ci/view/functest/job/functest-apex-virtual-suite-master/116/console

    Change-Id: Ic4dc98c793207fc32ff35852472742c92db6699c
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>