In comparison to other callback plugins like the default (stdout)
plugin, the role information for an executed task is missing in the
json output. To be complient to the provided task output containing
the name and uuid field, we've defined a similar data structure
containing the role information. This will only be added to the result
set if the task contained the necessary role information.
Change-Id: I8d94ba077e0bc90b5cf6510804bbd57c38184a9d
2dd4c5274b