Allow tests to run one at at a time, and halt on error.
Allow tests to run one at at a time, and halt on error.


Revision created by MOE tool push_codebase.
MOE_MIGRATION=6515

billy1380/appengine-pipelines,GoogleCloudPlatform/appengine-pipelines,ocadotechnology/appengine-pipelines,vendasta/appengine-pipelines,GoogleCloudPlatform/appengine-pipelines,Loudr/appengine-pipelines,billy1380/appengine-pipelines,billy1380/appengine-pipelines,VirusTotal/appengine-pipelines,GoogleCloudPlatform/appengine-pipelines,VirusTotal/appengine-pipelines,googlecloudplatform/appengine-pipelines,Loudr/appengine-pipelines,Loudr/appengine-pipelines,ocadotechnology/appengine-pipelines,aozarov/appengine-pipelines,Loudr/appengine-pipelines,aozarov/appengine-pipelines,vendasta/appengine-pipelines,googlecloudplatform/appengine-pipelines,ocadotechnology/appengine-pipelines,aozarov/appengine-pipelines,VirusTotal/appengine-pipelines,vendasta/appengine-pipelines,GoogleCloudPlatform/appengine-pipelines,aozarov/appengine-pipelines,VirusTotal/appengine-pipelines,Loudr/appengine-pipelines,billy1380/appengine-pipelines,googlecloudplatform/appengine-pipelines,vendasta/appengine-pipelines,vendasta/appengine-pipelines,VirusTotal/appengine-pipelines,GoogleCloudPlatform/appengine-pipelines,googlecloudplatform/appengine-pipelines,aozarov/appengine-pipelines,googlecloudplatform/appengine-pipelines,ocadotechnology/appengine-pipelines