Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "HA testcases"
  - HA testcases

    Modify HA testcases.rst file to include detail discribtion of the 8
    testcases. Rename the original rst file into HA testcases outline.rst.
    Please review and see if you need two of these file, or you prefer a
    single one, or maybe merge these two.

    as discussed,propose 8 HA testcases for mandatory  test cases.

    JIRA:

    Change-Id: Ie6cd5a68897bb0208932d2e1fec65cc59bfa25b4
    Signed-off-by: fuqiao@chinamobile.com