appsdk-bump-app-catalog 293 bumping sdk to 1507-dcce51f

sdk commit: RallySoftware/appsdk@65fca21140717ada7caa5c6e9522cf585ad7430f
author: Matt Parrish and Steve Neely
message: Trying to fix flakiness in CellEditingSpec by waiting for ScheduleStateTemplate to be rendered

sdk commit: RallySoftware/appsdk@f6a9b876bd66ada6c0325c2deaf9f05efb2ab723
author: Kyle Morse
message: DE19960: Eliminate test sets from new Iteration Status for good (in EE)

sdk commit: RallySoftware/appsdk@dcce51fd74e59220558a0805f0b9c48ed385fe78
author: Brandon Fryslie and Alan Brockett
message: Revert "Trying to fix flakiness in CellEditingSpec by waiting for ScheduleStateTemplate to be rendered"