Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Merge "Switch to public keystone endpoint" into stable/euphrates
  - Switch to public keystone endpoint

    It also reorders imports and removes dead code.

    Conflicts:
        functest/opnfv_tests/vnf/ims/orchestra_clearwaterims.py
        functest/opnfv_tests/vnf/ims/orchestra_openims.py

    Change-Id: I1e7bd03a4bc07df4705c9beed83a37a022ddbd52
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
    (cherry picked from commit 01cb2b343c0de7c67a4640d4d3794d924b68c6b9)