Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "temporary switch of opnfv/functest-* to ollivier/functest-* for alpine"
  - temporary switch of opnfv/functest-* to ollivier/functest-* for alpine

     - better requirement management on ollivier docker hub
     - add feature and vnf docker (components could be added but as they could be
     very long (~ > 3h), we focus on shorter tests for the moment (need testcase
    promotion mechanism to keep the control on overall test duration)

    Change-Id: Ia8130dba716a465cd9feaaac32eabb4534cbe031
    Signed-off-by: Morgan Richomme <morgan.richomme@orange.com>