This patch introduces the following changes.
1. Playbooks have been created to start collectd on different hosts.
2. A feature has been added that allows a user to start collectd containers
before running workloads, and stop the collectd containers after running
the workloads. This will help us in minimising the space used for storing
collectd data.
Change-Id: I7926884f461e97bc67453f46eef0121c46c7f19e
8e873e678a