Update git submodules

* Update docs/submodules/barometer from branch 'master'
  - Merge "Add support for 'collectd-master' container"
  - Add support for 'collectd-master' container

    'collectd-master' contains development versions of collectd
    with the latest features. It is based on master branch from
    collect repository.

    Change-Id: I720b5e5938b402281674ee73851c5f611e4d1178
    Signed-off-by: Radoslaw Jablonski <radoslawx.jablonski@intel.com>

diff --git a/docs/submodules/barometer b/docs/submodules/barometer
index fbbfee4..b52c942 160000 (submodule)
--- a/docs/submodules/barometer
+++ b/docs/submodules/barometer
@@ -1 +1 @@
-Subproject commit fbbfee45410a4a0766c61227751621c4463741bb
+Subproject commit b52c942a4fbfc5023780d23954de953b817c6dc0