Update git submodules

Update git submodules

* Update docs/submodules/barometer from branch 'master'
  - ansible: Add cleanup for grafana cache under host machine

    Previously cleaning cache directory for grafana(/var/lib/grafana)
    was missing and, because of that, changing influxdb_host variable
    value between one ansible deployment and another was not working.

    It was a problem because scripts in grafana container are expecting
    that cache directory will be empty during first run and, if some
    dashboards exists in cache already (even if they are left by
    previous deployment), old dashboards will be left untouched with
    possibly wrong configuration. This bug happened during deploying
    3 nodes scenarios more than once (collectd, grafana and influlxdb
    hosted on separate machines).

    Now cleanup is done by default and can be skipped using
    'clean_grafana_cache=false' value.

    Change-Id: Ib67cc3437b8a3a2c2930dd55cba44aef8e352cf2
    Signed-off-by: Radoslaw Jablonski <radoslawx.jablonski@intel.com>