Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Protect vs TypeErrors when cleaning stacks"
  - Protect vs TypeErrors when cleaning stacks

    It protects vs exceptions raised by shade when cleaning stacks.

    Traceback (most recent call last):
      File "/usr/lib/python2.7/site-packages/functest/opnfv_tests/vnf/ims/heat_ims.py", line 226, in clean
        self.cloud.delete_stack(self.stack.id, wait=True)
      File "/usr/lib/python2.7/site-packages/shade/openstackcloud.py", line 1416, in delete_stack
        marker=marker)
      File "/usr/lib/python2.7/site-packages/shade/_heat/event_utils.py", line 90, in poll_for_events
        stack_status = stack['stack_status']
    TypeError: 'NoneType' object has no attribute '__getitem__'

    Change-Id: I1a0ed0cd669d5234ca1ff3b6bbc9d1b13f14b02f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>