differential-dataflow-v0.13.2

Other

• Update to track timely changes (#554)
• Consolidation consolidation (#552)
• Pass description itself to builder (#551)
• Simplify ContainerChunker::push_into (#549)
• Remove time from MergeBatcher (#550)
• Changes to track timely master (#542)
• Remove (key, val) structure from merge batchers (#548)
• Merge batcher for flat container without key and value (#547)
• Move Batcher::seal to Builder (#546)
• Extract Builder from Trace (#545)
• Remove batcher from Trace (#544)
• Build against timely master (#539)