 minor amendments to pipeline_testing.py documentation
 minor amendments to pipeline_testing.py documentation

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