Currently, the barometer containers are built on the stable branch only.

This means that master and stable have the same versions.

As of stable/fraser, collectd is pinned to version 5.8 (released December 2017), however, there are a number of updates that have been made.

By splitting the container builds to stable/fraser and master, we can build the stable version (5.8) as well as test new collectd features on master (pinned commits)

After this change, new functest support will have to be implemented for the new plugins.

Suggested approach: 

• Split containers
• Increment collectd commit and add functest/doc for that feature
• Increment collectd commit and add functest/doc for next feature
• etc