Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - tag dovetail with 0.2.0

    JIRA: DOVETAIL-447

    docker images used

    yardstick danube.3.0
    functest cvp.0.2.0
    testapi cvp.0.2.0
    dovetail cvp.0.2.0

    main changes

    1, fix yardstick HA bugs
    2, fix functest sdnvpn offlinebugs
    3, fix dovetail https bugs, etc.
    for more info, refer to
    https://wiki.opnfv.org/display/dovetail/Running+history+for+the+dovetail+tool

    Change-Id: I4edb61b84ed80d8d7624f69db372fec60d73aa38
    Signed-off-by: MatthewLi <matthew.lijun@huawei.com>