Added tests for merge should be union
Added tests for merge should be union

CGATOxford/CGATPipelines,AntonioJBT/CGATPipeline_core,CGATOxford/CGATPipelines,AntonioJBT/CGATPipeline_core,CGATOxford/CGATPipelines,AntonioJBT/CGATPipeline_core,CGATOxford/CGATPipelines,CGATOxford/CGATPipelines,AntonioJBT/CGATPipeline_core