Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Drafting the first "refstack" version of the test scope document."
  - Drafting the first "refstack" version of the test scope document.

    To be aligned with the committers and agreed as the "foundation" list of
    test scope for moving forward with DoveTail test selection.
    Requires a majority of committer approvals prior to merging.

    Change-Id: I5fb091d2190a183d24ba9e766d19aba9e6a7c094
    Signed-off-by: ChristopherPrice <christopher.price@ericsson.com>
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>