Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 0a16f1267c3bd1c33def62861e6e1726097f239a
  - Merge changes from topic "OOM-1915"

    * changes:
      Update 'busybox' and 'haproxy' docker images path in tests
      Add role level tests for 'nexus' role
      Improve 'nexus' role testability

  - Update 'busybox' and 'haproxy' docker images path in tests

    At some point names of busybox and haproxy images
    have changed in nexus3.onap.org registry. This patch
    updates those names in testing framework.

    Change-Id: Iaad4976118bfcd708f2b8fccb8df61f6059ac1f4
    Issue-ID: OOM-1915
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>
  - Add role level tests for 'nexus' role

    Change-Id: If8decc241614e4fe802352cc783b59f8d7ec70b4
    Issue-ID: OOM-1915
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>
  - Improve 'nexus' role testability

    A change needed by related commit to allow building
    a custom nexus url.

    Change-Id: Iaa7e1d10d9621871e71863c77722cd635b7e1e4d
    Issue-ID: OOM-1915
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>