Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Additional Unit Tests for core modules"
  - Additional Unit Tests for core modules

    This patch adds unit tests for vnf and pytest_suite_runner.
    It also fixes several pylint warnings/errors.

    Additional tests are required to check args values.

    Co-Authored-By: Cédric Ollivier <cedric.ollivier@orange.com>
    Change-Id: I75a829233481655c794402830e1da037ab7cdb8d
    Signed-off-by: ashishk1994 <ashishk.iiit@gmail.com>