Update git submodules

Update git submodules

* Update docs/submodules/sfc from branch 'master'
  - Merge "Clean up Test Case code"
  - Clean up Test Case code

    Too much of duplicated code has been obeserved in
    test cases. With this patch a small refactoring is necessery
    to our test cases code. So they can be more generic and
    more flexible.

    To achieve that the addition of new parent class is essential, hence
    all the rest test case classes will inherit from the aforementioned
    parent class.

    Change-Id: I6a50d8330a06321742b3bb03cc999682d4a4e6a1
    Signed-off-by: Panagiotis Karalis <pkaralis@intracom-telecom.com>