Update git submodules

Update git submodules

* Update docs/submodules/barometer from branch 'master'
  - Merge "src: ensure hostname is included in collectd conf"
  - src: ensure hostname is included in collectd conf

    As part of the final step of copying all the appropriate configuration files to
    /opt/collectd/etc/collectd.conf.d make sure that the hostname is set.

    Change-Id: Iff1634ebcc647f7b6d6ec991d98bd199367f9d4e
    Signed-off-by: Maryam Tahhan <maryam.tahhan@intel.com>